Organic light-emitting diodes comprising carbene-transition metal complex emitters, and at least one compound selected from disilylcarbazoles, disilyldibenzofurans, disilyldibenzothiophenes, disilyldibenzophospholes, disilyldibenzothiophene s-oxides and disilyldibenzothiophene s,s-dioxides

ABSTRACT

The present invention relates to an organic light-emitting diode comprising an anode An and a cathode Ka and a light-emitting layer E which is arranged between the anode An and the cathode Ka and comprises at least one carbene complex and if appropriate at least one further layer, where the light-emitting layer E and/or the at least one further layer comprises at least one compound selected from disilylcarbazoles, disilyldibenzofurans, disilyldibenzothiophenes, disilyldibenzophospholes, disilyldibenzothiophene S-oxides and disilyldibenzothiophene S,S-dioxides, to a light-emitting layer comprising at least one of the aforementioned compounds and at least one carbene complex, to the use of the aforementioned compounds as matrix material, hole/exciton blocker material, electron/exciton blocker material, hole injection material, electron injection material, hole conductor material and/or electron conductor material, and to a device selected from the group consisting of stationary visual display units, mobile visual display units and illumination units comprising at least one inventive organic light-emitting diode; to selected disilylcarbazoles, disilyldibenzofurans, disilyldibenzothiophenes, disilyldibenzophospholes, disilyldibenzothiophene S-oxides and disilyldibenzothiophene S,S-dioxides, and to processes for their preparation.

The present invention relates to an organic light-emitting diodecomprising an anode An and a cathode Ka and a light-emitting layer Ewhich is arranged between the anode An and the cathode Ka and comprisesat least one carbene complex and if appropriate at least one furtherlayer, where the light-emitting layer E and/or the at least one furtherlayer comprises at least one compound selected from disilylcarbazoles,disilyldibenzofurans, disilyldibenzothiophenes,disilyldibenzophospholes, disilyldibenzothiophene S-oxides anddisilyldibenzothiophene S,S-dioxides, to a light-emitting layercomprising at least one of the aforementioned compounds and at least onecarbene complex, to the use of the aforementioned compounds as matrixmaterial, hole/exciton blocker material, electron/exciton blockermaterial, hole injection material, electron injection material, holeconductor material and/or electron conductor material, and to a deviceselected from the group consisting of stationary visual display units,mobile visual display units and illumination units comprising at leastone inventive organic light-emitting diode; to selecteddisilylcarbazoles, disilyldibenzofurans, disilyldibenzothiophenes,disilyldibenzophospholes, disilyldibenzothiophene S-oxides anddisilyldibenzothiophene S,S-dioxides, and to processes for theirpreparation.

Organic light-emitting diodes (OLEDs) exploit the property of materialsof emitting light when they are excited by electrical current. OLEDs areof particular interest as an alternative to cathode ray tubes and toliquid-crystal displays for producing flat visual display units. Owingto the very compact design and the intrinsically low power consumption,devices comprising OLEDs are suitable especially for mobileapplications, for example for applications in cellphones, laptops, etc.,and for illumination.

The basic principles of the way in which OLEDs work and suitablestructures (layers) of OLEDs are known to those skilled in the art andare specified, for example, in WO 2005/113704 and the literature citedtherein. The light-emitting materials (emitters) used may, as well asfluorescent materials (fluorescence emitters), be phosphorescentmaterials (phosphorescence emitters). The phosphorescence emitters aretypically organometallic complexes which, in contrast to thefluorescence emitters which exhibit singlet emission, exhibit tripletemission (triplet emitters) (M. A. Baldow et al., Appl. Phys. Lett.1999, 75, 4 to 6). For quantum-mechanical reasons, when the tripletemitters (phosphorescence emitters) are used, up to four times thequantum efficiency, energy efficiency and power efficiency is possible.In order to implement the advantages of the use of the organometallictriplet emitters (phosphorescence emitters) in practice, it is necessaryto provide device compositions which have a high operative lifetime, agood efficiency, a high stability to thermal stress and a low use andoperating voltage.

Such device compositions may, for example, comprise specific matrixmaterials in which the actual light emitter is present in distributedform. In addition, the compositions may comprise blocker materials, itbeing possible for hole blockers, exciton blockers and/or electronblockers to be present in the device compositions. Additionally oralternatively, the device compositions may further comprise holeinjection materials and/or electron injection materials and/or holeconductor materials and/or electron conductor materials. The selectionof the aforementioned materials which are used in combination with theactual light emitter has a significant influence on parameters includingthe efficiency and the lifetime of the OLEDs.

The prior art proposes numerous different materials for use in thedifferent layers of OLEDs.

US 2005/0238919 A1 relates to an organic light-emitting diode whichrelates to at least one aryl compound which comprises two or moresilicon atoms. The materials specified in US 2005/0238919 A1 arepreferably used as matrix materials in the light-emitting layer.According to US 2005/0238919 A1, the emitter materials used arepreferably phosphorescence emitters. They are preferably ortho-metalatedtransition metal complexes. More specific details with regard to theemitter material used are given in US 2005/0238919 A1 only in theexamples. Organic light-emitting diodes which, as well as the arylcompounds comprising silicon atoms, comprise at least one carbenecomplex as an emitter material are not disclosed in US 2005/0238919 A1.In addition, US 200570238919 A1 specifies a large number of differentlysubstituted silicon-comprising compounds, but only silicon-comprisingcompounds of the formulae (1-1) and (1-2) which have the followingformulae

are used in the examples of the present application.

Tsai et al., Adv. Mater., 2006, Vol. 18, No. 9, pages 1216 to 1220discloses organic blue-light emitting diodes which comprise9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)carbazole as matrixmaterial. The emitter materials used according to Tsai et al. are notcarbene complexes.

Yang et al., Angew. Chem. 2007, 119, 2470 to 2473 relates to bluelight-emitting heteroleptic iridium(III) complexes which are suitablefor use in phosphorescent OLEDs. In the examples according to Yang etal., the hole transport material and exciton blocker material used is9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)carbazole. The use ofcarbene complexes as emitter materials is not disclosed in Yang et al.

JP 2004253298 A relates to organic white light-emitting diodes in whichsubstituted triphenylsilanes are used as matrix materials.

When carbene complexes of the formula (I) specified below are used, itis necessary to use complementary materials (matrix materials, etc.)with a high triplet (high triplet energy) in order that light emissionof the carbene complex(es) is ensured. Typically used knowncomplementary materials with a high triplet, however, in combinationwith the carbene complexes of the formula (I), lead to OLEDs which donot exhibit good efficiencies and lifetimes.

It is therefore an object of the present invention, with respect to theprior art, to provide novel device compositions for OLEDs which have, asa light emitter, specific carbene complexes of the general formula (I)specified below. The materials suitable for the novel devicecompositions should be easy to obtain and, in combination with theemitter(s), bring about good efficiencies and good lifetimes in OLEDs.

This object is achieved by the provision of an organic light-emittingdiode comprising an anode An and a cathode Ka and a light-emitting layerE which is arranged between the anode An and the cathode Ka andcomprises at least one carbene complex of the general formula I

in which the symbols are each defined as follows:

-   M¹ is a metal atom selected from the group consisting of metals of    group IB, IIB, IIIB, IVB, VB, VIIB, VIIB, the lanthanides and IIIA    of the Periodic Table of the Elements (CAS version) in any oxidation    state possible for the particular metal atom; preferably selected    from the group consisting of groups IIB, IIIB, IVB, VB, VIIB, VIIB,    VIII of the Periodic Table of the Elements (CAS version), Cu and Eu,    more preferably selected from groups IB, VIIB, VIIB, VIII and Eu,    even more preferably selected from Cr, Mo, W, Mn, Tc, Re, Ru, Os,    Co, Rh, Ir, Fe, Nb, Pd, Pt, Cu, Ag, Au and Eu, even more preferably    Os, Rh, Ir, Ru, Pd and Pt, very especially preferably Ru, Rh, Ir and    Pt and more especially preferably Ir and Pt;-   carbene is a carbene ligand which may be uncharged or monoanionic    and mono-, bi- or tridentate; the carbene ligand may also be a bis-    or triscarbene ligand;-   L is a mono- or dianionic ligand, preferably monoanionic ligand,    which may be mono- or bidentate;-   K is an uncharged mono- or bidentate ligand;-   n is the number of carbene ligands, where n is at least 1 and the    carbene ligands in the complex of the formula I, when n>1, may be    the same or different;-   m is the number of ligands L, where m may be 0 or ≧1, and the    ligands L, when m>1, may be the same or different;-   o is the number of ligands K, where o may be 0 or ≧1, and the    ligands K, when o>1, may be the same or different;-   p is the charge of the complex: 0, 1, 2, 3 or 4; preferably 0, 1 or    2, more preferably 0;-   W is a monoanionic counterion; preferably halide, pseudohalide, BF₄    ⁻, PF₆ ⁻, AsF₆ ⁻, SbF₆ ⁻ or OAc⁻, more preferably Cl⁻, Br⁻, I⁻, CN⁻    or OAc⁻, most preferably Br⁻ or I⁻;    where the sum of n+m+o and the charge p depend on the oxidation    state and coordination number of the metal atom used, on the charge    of the complex and on the denticity of the carbene, L and K ligands,    and on the charge of the carbene and L ligands, with the condition    that n is at least 1;    and if appropriate at least one further layer,    wherein the organic light-emitting diode comprises at least one    compound of the general formula II which is present in the    light-emitting layer E and/or in the at least one further layer,

in which:

-   X is NR¹, S, O, PR¹, SO₂ or SO;-   R¹ is substituted or unsubstituted C₁-C₂₀-alkyl, substituted or    unsubstituted C₆-C₃₀-aryl, or substituted or unsubstituted    heteroaryl having from 5 to 30 ring atoms;-   R², R³, R⁴, R⁵, R⁶, R⁷    -   are each independently substituted or unsubstituted        C₁-C₂₀-alkyl, or substituted or unsubstituted C₆-C₃₀-aryl, or a        structure of the general formula (c)

R^(a), R^(b) are each independently substituted or unsubstitutedC₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, or substitutedor unsubstituted heteroaryl having from 5 to 30 ring atoms or asubstituent with donor or acceptor action selected from the groupconsisting of: C₁-C₂₀-alkoxy, C₆-C₃₀-aryloxy, C₁-C₂₀-alkylthio,C₆-C₃₀-arylthio, SiR¹⁴R¹⁵R¹⁶, halogen radicals, halogenated C₁-C₂₀-alkylradicals, carbonyl (—CO(R¹⁴)), carbonylthio (—C═O (SR¹⁴)), carbonyloxy(—C═O(OR¹⁴)), oxycarbonyl (—OC═O(R¹⁴)), thiocarbonyl (—SC═O(R¹⁴)), amino(—NR¹⁴R¹⁵), OH, pseudohalogen radicals, amido (—C═O (NR¹⁴)), —NR¹⁴C═O(R¹⁵), phosphonate (—P(O) (OR¹⁴)₂, phosphate (—OP(O) (OR¹⁴)₂), phosphine(—PR¹⁴R¹⁵), phosphine oxide (—P(O)R¹⁴ ₂), sulfate (—OS(O)₂OR¹⁴),sulfoxide (—S(O)R¹⁴), sulfonate (—S(O)₂OR¹⁴), sulfonyl (—S(O)₂R¹⁴),sulfonamide (—S(O)₂NR¹⁴R¹⁵), NO₂, boronic esters (—OB(OR¹⁴)₂), imino(—C═NR¹⁴R¹⁵)), borane radicals, stannane radicals, hydrazine radicals,hydrazone radicals, oxime radicals, nitroso groups, diazo groups, vinylgroups, sulfoximines, alanes, germanes, boroximes and borazines;

-   R¹⁴, R¹⁵, R¹⁶    -   are each independently substituted or unsubstituted        C₁-C₂₀-alkyl, or substituted or unsubstituted C₆-C₃₀-aryl;-   q, r are each independently 0, 1, 2 or 3; where, in the case when q    or r is 0, all substitutable positions of the aryl radical are    substituted by hydrogen,    where the radicals and indices in the group of the formula (c) X′″,    R^(5′″), R^(6′″), R^(7′″), R^(a′″), R^(b′″), q′″ and r′″ are each    independently as defined for the radicals and indices of the    compounds of the general formula (II) X, R⁵, R⁶, R⁷, R^(a), R^(b), q    and r.

The compounds of the general formula (II) are easy to obtain and havegood efficiencies when used in OLEDs both when used as matrix materialsin the light-emitting layer E and when used in at least one of thefurther layers of an OLED comprising at least one carbene complex of theformula (I) as a light emitter in combination with the actual emitter(s)of the general formula (I), and are suitable for providing OLEDs with along lifetime.

Depending on their substitution pattern, the compounds of the formula(II) can be used as a matrix in the light-emitting layer E, as ahole/exciton blocker, as an electron/exciton blocker, as hole injectionmaterials, as electron injection materials, as hole conductors and/or aselectron conductors. Corresponding layers of OLEDs are known to thoseskilled in the art and are specified, for example, in WO 2005/113704 orWO 2005/019373.

Structure of the Inventive OLEDs

The inventive organic light-emitting diode (OLED) has the followingstructure:

an anode (An) and a cathode (Ka) and a light-emitting layer E which isarranged between the anode (An) and the cathode (Ka) and comprises atleast one carbene complex of the general formula (I), and if appropriateat least one further layer.

Suitable further layers of the inventive OLEDs are the layers which areknown to those skilled in the art and are typically present in OLEDs.The inventive OLED preferably comprises at least one further layerselected from the group consisting of: at least one blocking layer forelectrons/excitons, at least one blocking layer for holes/excitons, atleast one hole injection layer, at least one hole conductor layer, atleast one electron injection layer and at least one electron conductorlayer.

It is additionally possible that a plurality of the aforementionedfunctions (electron/exciton blocker, hole/exciton blocker, holeinjection, hole conduction, electron injection, electron conduction) arecombined in one layer and, for example, are assumed by a single materialpresent in this layer. For example, a material used in the holeconductor layer may, in one embodiment, simultaneously block excitonsand/or electrons.

Furthermore, the individual aforementioned layers of the OLED may inturn be formed from 2 or more layers. For example, the hole conductorlayer may be formed from a layer into which holes are injected from theelectrode, and a layer which transports the holes away from thehole-injecting layer into the light-emitting layer. The electronconduction layer may likewise consist of a plurality of layers, forexample a layer in which electrons are injected through the electrode,and a layer which receives electrons from the electron injection layerand transports them into the light-emitting layer. The layers mentionedare each selected according to factors such as energy level, thermalresistance and charge carrier mobility, and also energy difference ofthe layers mentioned with the organic layers or the metal electrodes.The person skilled in the art is capable of selecting the constructionof the OLEDs such that it is adjusted optimally to the organic compoundsused in accordance with the invention as emitter substances.

In order to obtain particularly efficient OLEDs, for example, the HOMO(highest occupied molecular orbital) of the hole conductor layer shouldbe matched to the work function of the anode, and the LUMO (lowestunoccupied molecular orbital) of the electron conductor layer should bematched to the work function of the cathode, when the aforementionedlayers are present in the inventive OLEDs.

The inventive OLED may for example—in a preferred embodiment—be composedof the following layers:

1. anode

2. hole conductor layer

3. light-emitting layer

4. blocking layer for holes/excitons

5. electron conductor layer

6. cathode

Layer sequences different from the aforementioned construction are alsopossible, and are known to those skilled in the art. For example, it ispossible that the OLED does not have all of the layers mentioned; forexample, an OLED comprising layers (1) (anode), (3) (light-emittinglayer) and (6) (cathode) is likewise suitable, in which case thefunctions of layers (2) (hole conductor layer) and (4) (blocking layerfor holes/excitons) and (5) (electron conductor layer) are assumed bythe adjacent layers. OLEDs which have layers (1), (2), (3) and (6) orlayers (1), (3), (4), (5) and (6) are likewise suitable. In addition,the OLEDs may have a blocking layer for electrons/excitons between theanode (1) and the hole conductor layer (2).

The anode (1) is an electrode which provides positive charge carriers.It may be constructed, for example, from materials which comprise ametal, a mixture of different metals, a metal alloy, a metal oxide or amixture of different metal oxides. Alternatively, the anode may be aconductive polymer. Suitable metals comprise the metals of groups Ib,IVa, Va and VIa of the Periodic Table of the Elements, and thetransition metals of group VIIIa. When the anode is to be transparent,generally mixed metal oxides of groups IIb, IIIb and IVb of the PeriodicTable of the Elements (old IUPAC version) are used, for example indiumtin oxide (ITO). It is likewise possible that the anode (1) comprises anorganic material, for example polyaniline, as described, for example, inNature, Vol. 357, pages 477 to 479 (Jun. 11, 1992). At least either theanode or the cathode should be at least partly transparent in order tobe able to emit the light formed. The material used for the anode (1) ispreferably ITO.

Suitable hole conductor materials for layer (2) of the inventive OLEDsare disclosed, for example, in Kirk-Othmer Encyclopedia of ChemicalTechnology, 4th edition, vol. 18, pages 837 to 860, 1996. Bothhole-transporting molecules and polymers can be used as hole transportmaterial. Customarily used hole-transporting molecules are selected fromthe group consisting oftris[N-(1-naphthyl)-N-(phenylamino)]triphenylamine (1-NaphDATA),4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (α-NPD),N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD), tetrakis(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA),a-phenyl-4-N,N-diphenylaminostyrene (TPS), p-(diethylamino)benzaldehydediphenyl hydrazone (DEH), triphenylamine (TPA),bis[4-(N,N-diethylamino)-2-methylphenyl)(4-methylphenyl)methane (MPMP),1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP), 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane (DCZB),N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB),4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDTA), porphyrincompounds and phthalocyanines such as copper phthalocyanines.Customarily used hole-transporting polymers are selected from the groupconsisting of polyvinylcarbazoles, (phenylmethyl)polysilanes andpolyanilines. It is likewise possible to obtain hole-transportingpolymers by doping hole-transporting molecules into polymers such aspolystyrene and polycarbonate. Suitable hole-transporting molecules arethe molecules already mentioned above.

In addition—in a preferred embodiment—the carbene complexes of theformula (I) mentioned above as emitter materials may also be used ashole conductor materials, in which case the band gap of the at least onehole conductor material is generally greater than the band gap of theemitter material used. In the context of the present application, bandgap is understood to mean the triplet energy.

The light-emitting layer (3) comprises at least one carbene complex ofthe formula (I) as emitter material. This may be present alone ortogether with at least one matrix material in the light-emitting layer.Suitable matrix materials are, for example, phenothiazine S,S-dioxidederivatives or compounds which comprise aromatic or heteroaromatic ringsbonded via groups comprising carbonyl groups, as disclosed inWO2006/100298. In one embodiment, a further carbene complex of theformula (I) is used as matrix material, in which case the band gap ofthe carbene complex used as matrix material is generally greater thanthe band gap of the emitter material. In a further embodiment, acompound of the formula (II) is used as matrix material, in which casepreferred compounds of the formula (II) suitable as matrix material arespecified below.

The blocking layer for holes/excitons (4) may typically comprise holeblocker materials used in OLEDs, such as2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproin, (BCP)),bis(2-methyl-8-quinolinato)-4-phenylphenylato)aluminum(III) (BAlq),phenothiazine S,S-dioxide derivatives and1,3,5-tris(N-phenyl-2-benzylimidazole)-benzene (TPBI), TPBI also beingsuitable as an electron-conducting material.

In addition, the blocking layer for holes/excitons may comprise acompound of the general formula (II), in which case compounds of theformula (II) suitable with preference as hole blocker/exciton blockermaterials are specified below.

In a preferred embodiment, the present invention relates to an inventiveOLED comprising layers (1) anode, (2) hole conductor layer, (3)light-emitting layer, (4) blocking layer for holes/excitons, (5)electron conductor layer and (6) cathode, and if appropriate furtherlayers, the light-emitting layer (3) comprising at least one carbenecomplex of the formula (I) and the blocking layer for holes/excitons atleast one compound of the formula (II).

In a further preferred embodiment, the present invention relates to aninventive OLED comprising layers (1) anode, (2) hole conductor layer,(3) light-emitting layer, (4) blocking layer for holes/excitons, (5)electron conductor layer and (6) cathode, and if appropriate furtherlayers, the light-emitting layer (3) comprising at least one carbenecomplex of the formula (I) and at least one compound of the formula(II), and the blocking layer for holes/excitons at least one compound ofthe formula (II).

In a further embodiment, the present invention relates to an inventiveOLED comprising layers (1) anode, (2) hole conductor layer and/or (2′)blocking layer for electrons/excitons (the OLED may comprise both layers(2) and (2′), or else either layer (2) or layer (2′)), (3)light-emitting layer, (4) blocking layer for holes/excitons, (5)electron conductor layer and (6) cathode, and if appropriate furtherlayers, the blocking layer for electrons/excitons and/or the holeconductor layer and if appropriate the light-emitting layer (3)comprising at least one compound of the formula (II).

Suitable electron conductor materials for layer (5) of the inventiveOLEDs comprise metals chelated with oxinoid compounds, such as2,2′,2″-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole] (TPBI),tris(8-quinolinolato)aluminum (Alq₃), compounds based on phenanthroline,such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA=BCP) or4,7-diphenyl-1,10-phenanthroline (DPA), and azole compounds such as2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) and3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ). Thelayer (5) may serve either to facilitate electron transport or as abuffer layer or as a barrier layer in order to prevent quenching of theexciton at the interfaces of the layers of the OLED. The layer (5)preferably improves the mobility of the electrons and reduces quenchingof the exciton. In a preferred embodiment, TPBI is used as the electronconductor material.

Among the materials mentioned above as hole conductor materials andelectron conductor materials, some may fulfill several functions. Forexample, some of the electron-conducting materials are simultaneouslyhole-blocking materials when they have a low-lying HOMO. These may beused, for example, in the blocking layer for holes/excitons (4).However, it is likewise possible that the function as a hole/excitonblocker is also assumed by layer (5), such that layer (4) can bedispensed with.

The charge transport layers may also be electronically doped in order toimprove the transport properties of the materials used, in order firstlyto make the layer thicknesses more generous (avoidance of pinholes/shortcircuits) and in order secondly to minimize the operating voltage of thedevice. For example, the hole conductor materials may be doped withelectron acceptors; for example, it is possible to dope phthalocyaninesor arylamines such as TPD or TDTA withtetrafluorotetracyanoquinodimethane (F4-TCNQ). The electron conductormaterials may, for example, be doped with alkali metals, for exampleAlq₃ with lithium. Electronic doping is known to those skilled in theart and is disclosed, for example, in W. Gao, A. Kahn, J. Appl. Phys.,Vol. 94, No. 1, Jul. 1, 2003 (p-doped organic layers); A. G. Werner, F.Li, K. Harada, M. Pfeiffer, T. Fritz, K. Leo. Appl. Phys. Lett., Vol.82, No. 25, Jun. 23, 2003 and Pfeiffer et al., Organic Electronics 2003,4, 89-103.

The cathode (6) is an electrode which serves to introduce electrons ornegative charge carriers. Suitable materials for the cathode areselected from the group consisting of alkali metals of group Ia, forexample Li, Cs, alkaline earth metals of group IIa, for example calcium,barium or magnesium, metals of group IIb of the Periodic Table of theElements (old IUPAC version), comprising the lanthanides and actinides,for example samarium. In addition, it is also possible to use metalssuch as aluminum or indium, and combinations of all metals mentioned. Inaddition, lithium-comprising organometallic compounds or LiF may beapplied between the organic layer and the cathode in order to reduce theoperating voltage.

The OLED according to the present invention may additionally comprisefurther layers which are known to those skilled in the art. For example,between the layer (2) and the light-emitting layer (3) may be applied alayer which facilitates the transport of the positive charge and/ormatches the band gap of the layers to one another. Alternatively, thisfurther layer may serve as a protective layer. In an analogous manner,additional layers may be present between the light-emitting layer (3)and the layer (4) in order to facilitate the transport of the negativecharge and/or to match the band gap between the layers to one another.Alternatively, this layer may serve as a protective layer.

In a preferred embodiment, the inventive OLED comprises, in addition tolayers (1) to (6), at least one of the further layers specified below:

-   -   a hole injection layer between the anode (1) and the        hole-transporting layer (2);    -   a blocking layer for electrons between the hole-transporting        layer (2) and the light-emitting layer (3);    -   an electron injection layer between the electron-transporting        layer (5) and the cathode (6).

Those skilled in the art are aware of how suitable materials have to beselected (for example on the basis of electrochemical studies). Suitablematerials for the individual layers are known to those skilled in theart and are disclosed, for example, in WO 00/70655.

In addition, it is possible that some of the layers used in theinventive OLED are surface-treated in order to increase the efficiencyof charge carrier transport. The selection of the materials for each ofthe layers mentioned is preferably determined so as to obtain an OLEDwith high efficiency and lifetime.

The inventive OLED can be produced by methods known to those skilled inthe art. In general, the inventive OLED is produced by successive vapordeposition of the individual layers onto a suitable substrate. Suitablesubstrates are, for example, glass, inorganic semiconductors or polymerfilms. For the vapor deposition, it is possible to use customarytechniques such as thermal evaporation, chemical vapor deposition (CVD),physical vapor deposition (PVD) and others. In an alternative process,the organic layers of the OLEDs may be coated from solutions ordispersions in suitable solvents, for which coating techniques known tothose skilled in the art are employed.

In general, the different layers have the following thicknesses: anode(1) from 50 to 500 nm, preferably from 100 to 200 nm; hole-conductinglayer (2) from 5 to 100 nm, preferably from 20 to 80 nm, light-emittinglayer (3) from 1 to 100 nm, preferably from 10 to 80 nm, blocking layerfor holes/excitons (4) from 2 to 100 nm, preferably from 5 to 50 nm,electron-conducting layer (5) from 5 to 100 nm, preferably from 20 to 80nm, cathode (6) from 20 to 1000 nm, preferably from 30 to 500 nm. Therelative position of the recombination zone of holes and electrons inthe inventive OLED in relation to the cathode and hence the emissionspectrum of the OLED can be influenced, inter alia, by the relativethickness of each layer. This means that the thickness of the electrontransport layer should preferably be selected such that the position ofthe recombination zone is matched to the optical resonator property ofthe diode and hence to the emission wavelength of the emitter. The ratioof the layer thicknesses of the individual layers in the OLED depends onthe materials used. The layer thicknesses of any additional layers usedare known to those skilled in the art. It is possible that theelectron-conducting layer and/or the hole-conducting layer has/havegreater thicknesses than the layer thicknesses specified when they areelectrically doped.

According to the invention, the light-emitting layer E and/or at leastone of the further layers optionally present in the inventive OLEDcomprises at least one compound of the general formula (II). While theat least one compound of the general formula (II) is present in thelight-emitting layer E as a matrix material together with at least onecarbene complex of the general formula (I), the at least one compound ofthe general formula (II) can be used in the at least one further layerof the inventive OLED in each case alone or together with at least oneof the further aforementioned materials suitable for the correspondinglayers.

Substituted or unsubstituted C₁-C₂₀-alkyl is understood to mean alkylradicals having from 1 to 20 carbon atoms. Preference is given to C₁- toC₁₀-alkyl radicals, particular preference to C₁- to C₆-alkyl radicals.The alkyl radicals may be either straight-chain or branched or cyclic,where the alkyl radicals in the case of cyclic alkyl radicals have atleast 3 carbon atoms. In addition, the alkyl radicals may be substitutedby one or more substituents selected from the group consisting ofC₁-C₂₀-alkoxy, halogen, preferably F, and C₆-C₃₀-aryl which may in turnbe substituted or unsubstituted. Suitable aryl substituents and suitablealkoxy and halogen substituents are specified below. Examples ofsuitable alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl,heptyl and octyl, and also derivatives of the alkyl groups mentionedsubstituted by C₆-C₃₀-aryl, C₁-C₂₀-alkoxy and/or halogen, especially F,for example CF₃. Also included are both the n-isomers of the radicalsmentioned and branched isomers such as isopropyl, isobutyl, isopentyl,sec-butyl, tert-butyl, neopentyl, 3,3-dimethylbutyl, 3-ethylhexyl, etc.Preferred alkyl groups are methyl, ethyl, tert-butyl and CF₃.

Examples of suitable cyclic alkyl groups, which may likewise beunsubstituted or substituted by the above radicals specified for thealkyl groups, are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cycloheptyl, cyclooctyl, cyclononyl and cyclodecyl. If appropriate, thering systems may also be polycyclic ring systems such as decalinyl,norbornyl, bornanyl or adamantyl.

Suitable C₁-C₂₀-alkoxy and C₁-C₂₀-alkylthio groups derivecorrespondingly from the aforementioned C₁-C₂₀-alkyl radicals. Exampleshere include OCH₃, OC₂H₅, OC₃H₇, OC₄H₉ and OC₈H₁₇, and also SCH₃, SC₂H₅,SC₃H₇, SC₄H₉ and SC₈H₁₇. C₃H₇, C₄H₉ and C₈H₁₇ are understood to meanboth the n-isomers and branched isomers such as isopropyl, isobutyl,sec-butyl, tert-butyl and 2-ethylhexyl. Particularly preferred alkoxy oralkylthio groups are methoxy, ethoxy, n-octyloxy, 2-ethylhexyloxy andSCH₃.

Suitable halogen radicals or halogen substituents in the context of thepresent application are fluorine, chlorine, bromine and iodine,preferably fluorine, chlorine and bromine, more preferably fluorine andchlorine, most preferably fluorine.

Suitable pseudohalogen radicals in the context of the presentapplication are CN, SCN, OCN, N₃ and SeCN, preference being given to CNand SCN. Very particular preference is given to CN.

In the present invention, C₆-C₃₀-aryl refers to radicals which arederived from monocyclic, bicyclic or tricyclic aromatics which do notcomprise any ring heteroatoms. When the system is not a monocyclicsystem, the saturated form (perhydro form) or the partly unsaturatedform (for example the dihydro form or tetrahydro form) are also possiblefor the second ring in case of the designation “aryl”, provided that theparticular forms are known and stable. In other words, the term “aryl”in the present invention also comprises, for example, bicyclic ortricyclic radicals in which either both or all three radicals arearomatic, and also bicyclic or tricyclic radicals in which only one ringis aromatic, and also tricyclic radicals in which two rings arearomatic. Examples of aryl are: phenyl, naphthyl, indanyl,1,2-dihydronaphthenyl, 1,4-dihydronaphthenyl, indenyl, anthracenyl,phenanthrenyl or 1,2,3,4-tetrahydronaphthyl. Particular preference isgiven to C₆-C₁₀-aryl radicals, for example phenyl or naphthyl, veryparticular preference to C₆-aryl radicals, for example phenyl.

The C₆-C₃₀-aryl radicals may be unsubstituted or substituted by one ormore further radicals. Suitable further radicals are selected from thegroup consisting of C₁-C₂₀-alkyl, C₆-C₃₀-aryl or substituents with donoror acceptor action, suitable substituents with donor or acceptor actionbeing specified below. The C₆-C₃₀-aryl radicals are preferablyunsubstituted or substituted by one or more C₁-C₂₀-alkoxy groups, CN,CF₃, F or amino groups (NR¹⁴R¹⁵, where suitable R¹⁴ and R¹⁵ radicals arespecified above). Further preferred substitutions of the C₆-C₃₀-arylradicals depend on the end use of the compounds of the general formula(II) and are specified below.

Suitable C₆-C₃₀-aryloxy, C₆-C₃₀-alkylthio radicals derivecorrespondingly from the aforementioned C₆-C₃₀-aryl radicals. Particularpreference is given to phenoxy and phenylthio.

Unsubstituted or substituted heteroaryl having from 5 to 30 ring atomsis understood to mean monocyclic, bicyclic or tricyclic heteroaromaticswhich derive partly from the aforementioned aryl, in which at least onecarbon atom in the aryl base skeleton has been replaced by a heteroatom.Preferred heteroatoms are N, O and S. The heteroaryl radicals morepreferably have from 5 to 13 ring atoms. Especially preferably, the baseskeleton of the heteroaryl radicals is selected from systems such aspyridine and five-membered heteroaromatics such as thiophene, pyrrole,imidazole or furan. These base structures may optionally be fused to oneor two six-membered aromatic radicals. Suitable fused heteroaromaticsare carbazolyl, benzimidazolyl, benzofuryl, dibenzofuryl ordibenzothiophenyl. The base structure may be substituted at one, morethan one or all substitutable positions, suitable substituents being thesame as have already been specified under the definition of C₆-C₃₀-aryl.However, the heteroaryl radicals are preferably unsubstituted. Suitableheteroaryl radicals are, for example, pyridin-2-yl, pyridin-3-yl,pyridin-4-yl, thiophen-2-yl, thiophen-3-yl, pyrrol-2-yl, pyrrol-3-yl,furan-2-yl, furan-3-yl and imidazol-2-yl, and also the correspondingbenzofused radicals, especially carbazolyl, benzimidazolyl, benzofuryl,dibenzofuryl or dibenzothiophenyl.

In the context of the present application, groups with donor or acceptoraction are understood to mean the following groups:

C₁-C₂₀-alkoxy, C₆-C₃₀-aryloxy, C₁-C₂₀-alkylthio, C₆-C₃₀-arylthio,SiR¹⁴R¹⁵R¹⁶, halogen radicals, halogenated C₁-C₂₀-alkyl radicals,carbonyl (—CO(R¹⁴)), carbonylthio (—C═O (SR¹⁴)), carbonyloxy(—C═O(OR¹⁴)), oxycarbonyl (—OC═O(R¹⁴)), thiocarbonyl (—SC═O(R¹⁴)), amino(—NR¹⁴R¹⁵), OH, pseudohalogen radicals, amido (—C═O (NR¹⁴)), —NR¹⁴C═O(R¹⁵), phosphonate (—P(O) (OR¹⁴)₂, phosphate (—OP(O) (OR¹⁴)₂), phosphine(—PR¹⁴R¹⁵), phosphine oxide (—P(O)R¹⁴ ₂), sulfate (—0S(O)₂OR¹⁴),sulfoxide (S(O)R¹⁴), sulfonate (—S(O)₂OR¹⁴), sulfonyl (—S(O)₂R¹⁴),sulfonamide (—S(O)₂NR¹⁴R¹⁵), NO₂, boronic esters (—OB(OR¹⁴)₂), imino(—C═NR¹⁴R¹⁵)), borane radicals, stannane radicals, hydrazine radicals,hydrazone radicals, oxime radicals, nitroso groups, diazo groups, vinylgroups, sulfoximines, alanes, germanes, boroximes and borazines.

Preferred substituents with donor or acceptor action are selected fromthe group consisting of:

C₁- to C₂₀-alkoxy, preferably C₁-C₆-alkoxy, more preferably ethoxy ormethoxy; C₆-C₃₀-aryloxy, preferably C₆-C₁₀-aryloxy, more preferablyphenyloxy; SiR¹⁴R¹⁵R¹⁶ where R¹⁴, R¹⁵ and R¹⁶ are preferably eachindependently substituted or unsubstituted alkyl or substituted orunsubstituted phenyl; at least one of the R¹⁴, R¹⁵, R¹⁶ radicals is morepreferably substituted or unsubstituted phenyl; at least one of the R¹⁴,R¹⁵ and R¹⁶ radicals is most preferably substituted phenyl, suitablesubstituents having been specified above; halogen radicals, preferablyF, Cl, Br, more preferably F or Cl, most preferably F, halogenatedC₁-C₂₀-alkyl radicals, preferably halogenated C₁-C₆-alkyl radicals, mostpreferably fluorinated C₁-C₆-alkyl radicals, e.g. CF₃, CH₂F, CHF₂ orC₂F₅; amino, preferably dimethylamino, diethylamino or diphenylamino;OH, pseudohalogen radicals, preferably CN, SCN or OCN, more preferablyCN, —C(O)OC₁-C₄-alkyl, preferably —C(O)OMe, P(O)R₂, preferably P(O)Ph₂,or SO₂R₂, preferably SO₂Ph.

Very particularly preferred substituents with donor or acceptor actionare selected from the group consisting of methoxy, phenyloxy,halogenated C₁-C₄-alkyl, preferably CF₃, CH₂F, CHF₂, C₂F₅, halogen,preferably F, CN, SiR¹⁴R¹⁵R¹⁶, where suitable R¹⁴, R¹⁵ and R¹⁶ radicalshave already been mentioned, diphenylamino, —C(O)OC₁-C₄-alkyl,preferably —C(O)OMe, P(O)Ph₂, SO₂Ph.

The aforementioned groups with donor or acceptor action are not intendedto rule out the possibility that further aforementioned radicals andgroups may also have donor or acceptor action. For example, theaforementioned heteroaryl groups are likewise groups with donor oracceptor action, and the C₁-C₂₀-alkyl radicals are groups with donoraction.

The R¹⁴, R¹⁵ and R¹⁶ radicals mentioned in the aforementioned groupswith donor or acceptor action are each as already defined above, i.e.R¹⁴, R¹⁵, R¹⁶ are each independently:

substituted or unsubstituted C₁-C₂₀-alkyl or substituted orunsubstituted C₆-C₃₀-aryl, suitable and preferred alkyl and arylradicals having been specified above. More preferably, the R¹⁴, R¹⁵ andR¹⁶ radicals are C₁-C₆-alkyl, e.g. methyl, ethyl or i-propyl, phenyl. Ina preferred embodiment—in the case of SiR¹⁴R¹⁵R¹⁶—R¹⁴, R¹⁵ and R¹⁶ arepreferably each independently substituted or unsubstituted C₁-C₂₀-alkylor substituted or unsubstituted phenyl; more preferably, at least one ofthe R¹⁴, R¹⁵ and R¹⁶ radicals is substituted or unsubstituted phenyl;most preferably, at least one of the R¹⁴, R¹⁵ and R¹⁶ radicals issubstituted phenyl, suitable substituents having been specified above.

The expressions “electron-donating substituents” and“electron-withdrawing substituents” used additionally in the presentapplication are substituents with donor action (electron-donatingsubstituents) or substituents with acceptor action (electron-withdrawingsubstituents). Suitable electron-donating and electron-withdrawingsubstituents are thus the substituents which have already been specifiedabove for the substituents with donor or acceptor action.

Compounds of the Formula (II)

The compounds of the formula (II) are disilyl compounds in which theradicals and indices are each defined as follows:

-   X is NR¹, S, O, PR¹, SO₂ or SO; preferably NR¹, S or O;-   R¹ is substituted or unsubstituted C₁-C₂₀-alkyl, substituted or    unsubstituted C₆-C₃₀-aryl, or substituted or unsubstituted    heteroaryl having from 5 to 30 ring atoms; preferably substituted or    unsubstituted C₁-C₂₀-alkyl or substituted or unsubstituted    C₆-C₃₀-aryl, more preferably substituted or unsubstituted    C₆-C₁₀-aryl or unsubstituted C₁-C₂₀-alkyl, most preferably    substituted or unsubstituted phenyl, suitable substituents having    been specified above;-   R², R³, R⁴, R⁵, R⁶, R⁷    -   are each independently substituted or unsubstituted C₁-C₂₀-alkyl        or substituted or unsubstituted C₆-C₃₀-aryl or a structure of        the general formula (c);    -   preferably at least one of the R², R³ and R⁴ radicals and/or at        least one of the R⁵, R⁶ and R⁷ radicals is substituted or        unsubstituted C₆-C₃₀-aryl, more preferably substituted or        unsubstituted C₆-C₁₀-aryl, most preferably substituted or        unsubstituted phenyl, suitable substituents having been        specified above, and/or one of the R², R³ and R⁴ radicals and/or        one of the R⁵, R⁶ and R⁷ radicals is a radical of the structure        (c);-   R^(a), R^(b) are each independently substituted or unsubstituted    C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, substituted    or unsubstituted heteroaryl having from 5 to 30 ring atoms, or a    substituent with donor or acceptor action, suitable and preferred    substituents with donor or acceptor action having been specified    above;-   R¹⁴, R¹⁵, R¹⁶    -   are each independently substituted or unsubstituted C₁-C₂₀-alkyl        or substituted or unsubstituted C₆-C₃₀-aryl, preferably        substituted or unsubstituted C₁-C₆-alkyl or substituted or        unsubstituted C₆-C₁₀-aryl, where R¹⁴, R¹⁵ and R¹⁶ are more        preferably each independently substituted or unsubstituted        C₁-C₂₀-alkyl or substituted or unsubstituted phenyl; more        preferably, at least one of the R¹⁴, R¹⁵ and R¹⁶ radicals is        substituted or unsubstituted phenyl; most preferably, at least        one of the R¹⁴, R¹⁵ and R¹⁶ radicals is substituted phenyl,        suitable substituents having been specified above;-   q, r are each independently 0, 1, 2 or 3, where, when q or r is 0,    all substitutable positions of the aryl radical bear hydrogen atoms,    preferably 0.

In one embodiment, the present invention relates to an inventive organiclight-emitting diode in which the X group is NR¹, where the R¹ radicalhas already been defined above, in which at least one of the R¹ to R⁷,R^(a) and R^(b) radicals in the compounds of the formula (II) comprisesat least one heteroatom. Preferred heteroatoms are N, Si, halogen,especially F or Cl, O, S or P. The heteroatom may be present in the formof a substituent on at least one of the R¹ to R⁷, R^(a) or R^(b)radicals, or in the form of part of a substituent, or be present in thebase structure of at least one of the R¹ to R⁷, R^(a) or R^(b) radicals.Suitable substituents or base structures are known to those skilled inthe art and are specified under the definitions of the R¹ to R⁷, R^(a)or R^(b) radicals.

A preferred embodiment of the present invention relates to an organiclight-emitting diode according to the present invention, in which atleast one of the R², R³ and R⁴ radicals and/or at least one of the R⁵,R⁶ and R⁷ radicals in the compounds of the formula (II) is substitutedor unsubstituted C₆-C₃₀-aryl. Preferred aryl radicals and theirsubstituents have already been specified above.

A further embodiment of the present invention relates to an inventiveorganic light-emitting diode in which the compound of the generalformula (II) is a 3,6-disilyl-substituted compound of the generalformula (IIa):

in which:

-   X is NR¹, S, O, PR¹, SO₂ or SO; preferably NR¹, S or O; more    preferably NR¹;-   R¹ is substituted or unsubstituted C₁-C₂₀-alkyl, substituted or    unsubstituted C₆-C₃₀-aryl, or substituted or unsubstituted    heteroaryl having from 5 to 30 ring atoms; preferably substituted or    unsubstituted C₆-C₃₀-aryl or substituted or unsubstituted    C₁-C₂₀-alkyl, more preferably substituted or unsubstituted    C₆-C₁₀-aryl or unsubstituted C₁-C₂₀-alkyl, most preferably    substituted or unsubstituted phenyl, suitable substituents having    been specified above;-   R², R³, R⁴, R⁵, R⁶, R⁷    -   are each independently substituted or unsubstituted C₁-C₂₀-alkyl        or substituted or unsubstituted C₆-C₃₀-aryl or a structure of        the general formula (c);    -   preferably at least one of the R², R³ and R⁴ radicals and/or at        least one of the R⁵, R⁶ and R⁷ radicals is substituted or        unsubstituted C₆-C₃₀-aryl, more preferably substituted or        unsubstituted C₆-C₁₀-aryl, most preferably substituted or        unsubstituted phenyl, suitable substituents having been        specified above, and/or one of the R², R³ and R⁴ radicals and/or        one of the R⁵, R⁶ and R⁷ radicals is a radical of the structure        (c);-   R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³    -   are each independently hydrogen or are as defined for R^(a) and        R^(b), i.e. are each independently substituted or unsubstituted        C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl,        substituted or unsubstituted heteroaryl having from 5 to 30 ring        atoms or a substituent with donor or acceptor action, suitable        substituents with donor or acceptor action having been specified        above; preferably hydrogen, substituted or unsubstituted        C₁-C₆-alkyl, substituted or unsubstituted C₆-C₁₀-aryl or        SiR¹⁴R¹⁵R¹⁶; more preferably hydrogen, methyl, ethyl, phenyl,        CF₃ or SiR¹⁴R¹⁵R¹⁶, where R¹⁴, R¹⁵ and R¹⁶ are preferably each        independently substituted or unsubstituted C₁-C₂₀-alkyl or        substituted or unsubstituted phenyl; more preferably, at least        one of the R¹⁴, R¹⁵ and R¹⁶ radicals is substituted or        unsubstituted phenyl; most preferably, at least one of the R¹⁴,        R¹⁵ and R¹⁶ radicals is substituted phenyl, suitable        substituents having been specified above;        and the further radicals and indices R¹⁴, R¹⁵, R¹⁶ are each as        defined above.

In a particularly preferred embodiment, the compounds of the formula(II) used in the inventive organic light-emitting diodes have thefollowing definitions for the R¹ to R⁷, R^(a) and R^(b) radicals and theX group:

-   X is NR¹;-   R¹ is substituted or unsubstituted C₆-C₃₀-aryl or substituted or    unsubstituted heteroaryl having from 5 to 30 ring atoms, preferably    substituted or unsubstituted C₆-C₁₀-aryl, more preferably    substituted or unsubstituted phenyl, suitable substituents having    been specified above;-   R², R³, R⁴, R⁵, R⁶, R⁷    -   are each independently substituted or unsubstituted C₁-C₂₀-alkyl        or substituted or unsubstituted C₆-C₃₀-aryl, or a structure of        the general formula (c), preferably each independently        substituted or unsubstituted C₁-C₆-alkyl or substituted or        unsubstituted C₆-C₁₀-aryl, more preferably substituted or        unsubstituted C₁-C₆-alkyl or substituted or unsubstituted        phenyl; where, in one embodiment, at least one of the R², R³ and        R⁴ radicals and/or at least one of the R⁵, R⁶ and R⁷ radicals is        substituted or unsubstituted C₆-C₃₀-aryl, preferably substituted        or unsubstituted C₆-C₁₀-aryl, more preferably substituted or        unsubstituted phenyl; preferred substituents having been        specified above;-   R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³    -   are each independently hydrogen or are each as defined for R^(a)        and R^(b), i.e. are each independently substituted or        unsubstituted substituted or unsubstituted C₆-C₃₀-aryl,        substituted or unsubstituted heteroaryl having from 5 to 30 ring        atoms or a substituent with donor or acceptor action, suitable        substituents with donor or acceptor action already having been        specified above; preferably hydrogen, substituted or        unsubstituted C₁-C₆-alkyl, substituted or unsubstituted        C₆-C₁₀-aryl or siR¹⁴R¹⁵R¹⁶; more preferably hydrogen, methyl,        ethyl, phenyl, CF₃ or SiR¹⁴R¹⁵R¹⁶;-   R¹⁴, R¹⁵, R¹⁶    -   are each independently substituted or unsubstituted C₁-C₂₀-alkyl        or substituted or unsubstituted C₆-C₃₀-aryl, preferably        substituted or unsubstituted C₁-C₆-alkyl or substituted or        unsubstituted C₆-C₁₀-aryl, where R¹⁴, R¹⁵ and R¹⁶ are more        preferably each independently substituted or unsubstituted        C₁-C₂₀-alkyl or substituted or unsubstituted phenyl; more        preferably, at least one of the R¹⁴, R¹⁵ and R¹⁶ radicals is        substituted or unsubstituted phenyl; most preferably, at least        one of the R¹⁴, R¹⁵ and R¹⁶ radicals is substituted phenyl,        suitable substituents having been specified above.

Preferred compounds of the formula (II) for use in the inventive OLEDsare detailed below:

-   i) preferred compounds of the formula (II) in which X is NR¹ or PR¹    (the preferred carbazole derivatives (X═NR¹) are detailed    hereinafter). The present invention likewise comprises those    compounds in which the N in the formulae below is replaced by    P(X═PR¹):-   ia) compounds of the formula (II) which are more preferably suitable    as a matrix and/or electron/exciton blocker:

-   ib) compounds of the formula (II) which are more preferably suitable    as a matrix and/or hole/exciton blocker:

-   ic) compounds of the formula (II) which are more preferably suitable    as a matrix:

-   id) further preferred compounds of the formula (II) which are more    preferably used suitably as a matrix and/or hole/exciton blocker    and/or electron/exciton blocker:

-   ii) preferred compounds of the formula (II) in which X is O, S, SO,    SO₂:-   iia) compounds of the formula (II) which are more preferably    suitable as a matrix and/or electron/exciton blocker:

-   iib) compounds of the formula (II) which are more preferably    suitable as a matrix and/or hole/exciton blocker:

X in the formulae specified under iia) and iib) is preferably O, S, SOor SO₂.

In a further preferred embodiment, the present invention relates to anorganic light-emitting diode in which a compound of the formula (II) isused, in which the R¹ radical and/or at least one of the radicals fromthe group of R², R³ and R⁴ and/or at least one of the radicals from thegroup of R⁵, R⁶ and R⁷ is independently substituted or unsubstitutedC₆-aryl of the following formula:

in which

-   p is 0, 1, 2, 3, 4 or 5, preferably 0, 1, 2 or 3, more preferably 0,    1 or 2;-   R¹⁷ is hydrogen, substituted or unsubstituted C₁-C₂₀-alkyl,    substituted or unsubstituted C₆-C₃₀-aryl, substituted or    unsubstituted heteroaryl having from 5 to 30 ring atoms, a    substituent with donor or acceptor action, suitable substituents    with donor or acceptor action having been specified above, or a    radical of the general formula a or b

in which

-   X′ is N or P, and    the radicals and indices X″, R^(2′), R^(3′), R^(4′), R^(5′), R^(5″),    R^(6′), R^(6″), R^(7′), R^(7″), R^(a′), R^(a″), R^(b′), R^(b″), q′,    q″, r′ and r″ are each independently as defined for the radicals and    indices X, R², R³, R⁴, R⁵, R⁶, R⁷, R^(a), R^(b), q and r;    or    one of the R², R³ and R⁴ radicals and/or one of the R⁵, R⁶ and R⁷    radicals is a radical of the general formula c

in which the radicals and indices X′″, R^(5′″), R^(6′″), R^(7′″),R^(a′″), R^(b′″), q′″ and r′″ are each independently as defined for theradicals and indices X, R⁵, R⁶, R⁷, R^(a), R^(b), q and r.

Preferred R¹⁷ radicals are selected from the group consisting ofhydrogen, substituted or unsubstituted C₁-C₆-alkyl, substituted orunsubstituted C₆-C₁₀-aryl, substituted or unsubstituted heteroarylhaving from 5 to 13 ring atoms, preferably carbazolyl, a substituentwith donor or acceptor action selected from the group consisting of C₁-to C₂₀-alkoxy, preferably C₁-C₆-alkoxy, more preferably ethoxy ormethoxy; C₆-C₃₀-aryloxy, preferably C₆-C₁₀-aryloxy, more preferablyphenyloxy; SiR¹⁴R¹⁵R¹⁶; halogen radicals, preferably F, Cl, Br, morepreferably F or Cl, most preferably F, halogenated C₁-C₂₀-alkylradicals, preferably halogenated C₁-C₆-alkyl radicals, most preferablyfluorinated C₁-C₆-alkyl radicals, e.g. CF₃, CH₂F, CHF₂ or C₂F₅; amino,preferably dimethylamino, diethylamino or diphenylamino, more preferablydiphenylamino; OH, pseudohalogen radicals, preferably CN, SCN or OCN,more preferably CN; C(O)OC₁-C₄-alkyl, preferably —C(O)OMe, P(O)Ph₂,SO₂Ph, where R¹⁴, R¹⁵ and R¹⁶ are each independently substituted orunsubstituted C₁- to C₆-alkyl or substituted or unsubstituted C₆- toC₁₀-aryl and—in the case of SiR¹⁴R¹⁵R¹⁶ are preferably eachindependently substituted or unsubstituted alkyl or substituted orunsubstituted phenyl; more preferably, at least one of the R¹⁴, R¹⁵ andR¹⁶ radicals is substituted or unsubstituted phenyl; most preferably, atleast one of the R¹⁴, R¹⁵ and R¹⁶ radicals is substituted phenyl,suitable substituents having been specified above. More preferably, theR¹⁷ radicals are each independently selected from the group consistingof methoxy, phenyloxy, unsubstituted C₁-C₄-alkyl, preferably methyl,halogenated C₁-C₄-alkyl, preferably CF₃, CHF₂, CH₂F, C₂F₅, CN, halogen,preferably F, —C(O)O—C₁-C₄-alkyl, preferably —C(O)OMe, P(O)Ph₂, andsubstituted or unsubstituted heteroaryl having from 5 to 13 ring atoms,preferably carbazolyl.

In a further embodiment of the present invention, the indices r and q inthe compounds of the formula (II) are each 0, i.e. all substitutablepositions of the aryl groups bear hydrogen atoms. For all other radicalsand indices, the aforementioned definitions apply.

The compounds of the formula (II) used in accordance with the inventionmay be used in different layers of the inventive organic light-emittingdiode, suitable and preferred layer sequences in the inventive OLEDshaving been specified above.

In one embodiment, the present invention relates to organiclight-emitting diodes in which the compounds of the formula (II) areused as a matrix in the light-emitting layer E.

In a further embodiment, the present invention relates to an inventiveorganic light-emitting diode in which the compounds of the formula (II)are used in the blocking layer for electrons as an electron/excitonblocker and/or in the hole injection layer and/or in the hole conductorlayer. It is likewise possible that the compounds of the formula (II)are additionally present in the light-emitting layer E and/or one ormore of the layers specified below.

In a further embodiment, the present invention relates to an inventiveorganic light-emitting diode in which the compounds of the formula (II)are used in the blocking layer for holes as a hole/exciton blockerand/or in the electron injection layer and/or in the electron conductorlayer. It is likewise possible that the compounds of the formula (II)are additionally present in the light-emitting layer E and/or one ormore of the aforementioned layers.

Depending on the layer in which the compounds of the formula (II) areused, the compounds of the formula (II) have different preferred R¹, R²,R³, R⁴, R⁵, R⁶, R⁷, R^(a) and R^(b) radicals and different X groups. Inaddition to the function of the layer in which the compounds of theformula (II) can be used in the inventive OLED, the R¹ to R⁷, R^(a) andR^(b) radicals and the X group of the compounds of the formula (II) areadditionally dependent on the electronic properties (relative positionsof the HOMOs and LUMOs) of the particular layers used in the inventiveOLED. It is thus possible, by virtue of suitable substitution of thecompounds of the formula (II), to adjust the HOMO and LUMO orbitalpositions to the further layers used in the inventive OLED, and thus toachieve a high stability of the OLED and hence a long operative lifetimeand good efficiencies.

The principles regarding the relative positions of HOMO and LUMO in theindividual layers of an OLED are known to those skilled in the art. Theprinciples, by way of example with regard to the properties of theblocking layer for electrons and of the blocking layer for holes, inrelation to the light-emitting layer are detailed hereinafter:

The LUMO of the blocking layer for electrons is energetically higherthan the LUMO of the materials used in the light-emitting layer (both ofthe emitter material and of any matrix materials used). The greater theenergetic difference of the LUMOs of the blocking layer for electronsand of the materials in the light-emitting layer, the better are theelectron- and/or exciton-blocking properties of the blocking layer forelectrons. Suitable substitution patterns of the compounds of theformula (II) suitable as electron and/or exciton blocker materials thusdepend upon factors including the electronic properties (especially theposition of the LUMO) of the materials used in the light-emitting layer.

The HOMO of the blocking layer for electrons is energetically higherthan the HOMOs of the materials present in the light-emitting layer(both of the emitter materials and of any matrix materials present). Thegreater the energetic difference of the HOMOs of the blocking layer forholes and of the materials present in the light-emitting layer, thebetter are the hole- and/or exciton-blocking properties of the blockinglayer for holes. Suitable substitution patterns of the compounds of theformula (II) suitable as hole and/or exciton blocker materials thusdepend upon factors including the electronic properties (especially theposition of the HOMOs) of the materials present in the light-emittinglayer.

Comparable considerations relating to the relative position of the HOMOsand LUMOs of the different layers used in the inventive OLED apply tothe further layers which may be used in the OLED and are known to thoseskilled in the art.

Preferably suitable R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R^(a) and R^(b) radicalsof the compounds of the formula (II), depending on their use indifferent layers of the inventive OLED, are specified below. It ispointed out that preferred substitutions of the compounds of the formula(II) other than those specified below may in principle be suitable foruse in the different layers—depending on the electronic properties ofthe further layers of the OLED, especially depending on the electronicproperties of the light-emitting layer.

Compounds of the General Formula (II) which are Especially Suitable forUse in the Light-Emitting Layer E as Matrix Materials, and for Use inthe Blocking Layer for Electrons, in the Hole Injection Layer and/or inthe Hole Conductor Layer

A preferred embodiment of the present invention relates to an organiclight-emitting diode in which the compounds of the formula (II) are usedin a blocking layer for electrons, in a hole injection layer and/or in ahole conductor layer and/or in the light-emitting layer E as matrixmaterials.

Preferred compounds of the formula (II) which can be used in at leastone of the aforementioned layers have at least one R¹, R², R³, R⁴, R⁵,R⁶ or R⁷ radical which is substituted or unsubstituted C₁-C₂₀-alkyl,heteroaryl having from 5 to 30 ring atoms, substituted or unsubstitutedC₆-C₃₀-aryl, alkyl-substituted C₆-C₃₀-aryl (where “alkyl-substituted”means C₁-C₂₀-alkyl-substituted C₆-C₃₀-aryl), C₆-C₃₀-aryl substituted byat least one substituent with donor action, or C₆-C₃₀-aryl substitutedby heteroaryl having from 5 to 30 ring atoms, or a substituent withdonor action or, in the case of R², R³, R⁴, R⁵, R⁶ or R⁷, hydrogen.

Suitable substituents with donor action (electron-donating radicals) arepreferably selected from the group consisting of substituted andunsubstituted C₁-C₆-alkyl, preferably methyl, substituted andunsubstituted C₆-C₁₀-aryl, substituted and unsubstituted electron-richheteroaryl having from five to 30 ring atoms, preferably selected fromthe group consisting of carbazolyl, pyrrolyl, imidazolyl, pyrazolyl,triazolyl, oxazolyl, thiophenyl, preferably carbazolyl, pyrrolyl andthiophenyl, more preferably carbazolyl, C₁-C₂₀-alkoxy, preferablyC₁-C₆-alkoxy, more preferably methoxy and ethoxy, C₆-C₃₀-aryloxy,preferably C₆-C₁₀-aryloxy, more preferably phenyloxy, C₁-C₂₀-alkylthio,preferably C₁-C₆-alkylthio, more preferably —SCH₃, C₆-C₃₀-arylthio,preferably C₆-C₁₀-arylthio, more preferably —SPh, F, SiR¹⁴R¹⁵R¹⁶ whereR¹⁴, R¹⁵ and R¹⁶ are preferably donor-substituted phenyl groups, amino(—NR¹⁴R¹⁵), preferably diphenylamino, phosphine (—PR¹⁴R¹⁵), hydrazineradicals, OH, donor-substituted vinyl groups, where R¹⁴, R¹⁵ and R¹⁶ areeach as defined above and are preferably donor-substituted phenylgroups.

Very particularly preferred substituents with donor action are selectedfrom the group consisting of diphenylamino, carbazolyl, methoxy,phenoxy, very particular preference being given especially to methoxyand carbazolyl.

More preferably, the at least one radical which is used in theaforementioned layers is a C₆-aryl radical of the formula (d)substituted by at least one substituent with donor action and/or atleast one heteroaryl radical having from 5 to 30 ring atoms

in which:

-   p′ is 1, 2, 3, 4 or 5, preferably 1, 2 or 3, more preferably 1 or 2,    and-   R¹⁸ is in each case independently substituted or unsubstituted    C₁-C₆-alkyl, preferably methyl, substituted or unsubstituted    C₆-C₁₀-aryl, C₁-C₂₀-alkoxy, preferably C₁-C₆-alkoxy, more preferably    methoxy and ethoxy, C₆-C₃₀-aryloxy, preferably C₆-C₁₀-aryloxy, more    preferably phenyloxy, C₁-C₂₀-alkylthio, preferably C₁-C₆-alkylthio,    more preferably —SCH₃, C₆-C₃₀-arylthio, preferably C₆-C₁₀-arylthio,    more preferably —SPh, SiR¹⁴R¹⁵R¹⁶ where R¹⁴, R¹⁵ and R¹⁶ are each as    defined above and are preferably each donor-substituted phenyl    groups, amino (—NR¹⁴R¹⁵), preferably diphenylamino, amido (—NR¹⁴    (C═O (R¹⁵)), phosphine (—PR¹⁴R¹⁵), hydrazine radicals, OH,    donor-substituted vinyl groups, where R¹⁴, R¹⁵ and R¹⁶ are each as    defined above and are preferably each donor-substituted phenyl    groups,    -   or R¹⁸ is substituted or unsubstituted electron-rich heteroaryl        having from five to 30 ring atoms, preferably selected from the        group consisting of carbazolyl, pyrrolyl, imidazolyl, pyrazolyl,        triazolyl, oxazolyl, thiophenyl, more preferably carbazolyl,        pyrrolyl and thiophenyl.

Preferred R¹⁸ groups are selected from the group consisting of methoxy,ethoxy, phenoxy, very particular preference being given especially tomethoxy, and carbazolyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl,oxazolyl and thiophenyl, very particular preference being given tomethoxy, phenyloxy, carbazolyl and NR¹⁴R¹⁵ where R¹⁴ and R¹⁵ are eachphenyl or tolyl.

More preferably, the compounds of the formula (II) used in theaforementioned layers have at least one R¹, R², R³, R⁴, R⁵, R⁶ or R⁷radical selected from the group consisting of

In a preferred embodiment, at least one R¹ radical is a C₆-aryl radicalof the formula (d) substituted by at least one substituent with donoraction and/or at least one heteroaryl radical having from 5 to 30 ringatoms;

and the R², R³, R⁴, R⁵, R⁶ and R⁷ radicals are preferably each phenyl,methyl or methoxy- or phenyloxy substituted phenyl.

Use of the Compounds of the Formula (II) in the Light-Emitting Layer Eas Matrix Material and/or in a Blocking Layer for Holes, an ElectronInjection Layer and/or an Electron Conductor Layer

The present invention further relates to an inventive organiclight-emitting diode in which at least one compound of the formula (II)is present in at least one of the layers selected from light-emittinglayer E, blocking layer for holes, electron injection layer and electronconductor layer.

Preferred compounds of the formula (II) used in the aforementionedlayers have at least one R¹, R², R³, R⁴, R⁵, R⁶ or R⁷ radical which isC₁- to C₂₀-alkyl substituted by at least one substituent with acceptoraction (electron-withdrawing radical), C₆-C₃₀-aryl substituted by atleast one substituent with acceptor action, C₆-C₃₀-aryl substituted byat least one heteroaryl radical having from 5 to 30 ring atoms, or asubstituent with acceptor action.

Suitable substituents with acceptor action (electron-withdrawingradicals) are selected from the group consisting of electron-deficientheteroaryls having from 5 to 30 ring atoms, carbonyl (—CO(R¹⁴)),carbonylthio (—C═O (SR¹⁴)), carbonyloxy (—C═O (OR¹⁴)), oxycarbonyl(—OC═O (R¹⁴)), thiocarbonyl (—SC═O(R¹⁴)), OH, halogen,halogen-substituted C₁-C₂₀-alkyl, pseudohalogen radicals, amido (—C═O(NR¹⁴), phosphonate (—P(O) (OR¹⁴)₂), phosphate (—OP(O) (OR¹⁴)₂),phosphine oxide (—P(O)R¹⁴R¹⁵), sulfonyl (—S(O)₂R¹⁴), sulfonate(—S(O)₂OR¹⁴), sulfate (—OS(O)₂OR¹⁴), sulfoxide (—S(O)R¹⁴), sulfonamide(—S(O)₂NR¹⁴R¹⁵), NO₂), boronic esters (—OB(OR¹⁴)₂), imino (—C═NR¹⁴R¹⁵)),hydrazone radicals, oxime radicals, nitroso groups, diazo groups,sulfoximines, SiR¹⁴R¹⁵R¹⁶, borane radicals, stannane radicals,acceptor-substituted vinyl groups, boroxines and borazines, where R¹⁴,R¹⁵ and R¹⁶ are each substituted or unsubstituted C₁-C₂₀-alkyl,preferably substituted or unsubstituted C₁-C₆-alkyl, or substituted orunsubstituted C₆-C₃₀-aryl, preferably substituted or unsubstitutedC₆-C₁₀-aryl.

Preferred substituents with acceptor action are selected from the groupconsisting of halogen, preferably F, halogen-substituted alkyl,preferably CF₃, CH₂F, CHF₂, C₂F₅, C₃F₃H₄, pseudohalogen, preferably CN,carbonyloxy (—C═O (OR¹⁴)), preferably —C═O(OCH₃), phosphine oxide,preferably P(O)Ph₂, and sulfonyl, preferably S(O)₂Ph₂. The at least oneradical which is used in the aforementioned layers is more preferably asubstituted C₆-aryl radical of the formula (e)

in which:

-   p″ is 1, 2, 3, 4 or 5, preferably 1, 2 or 3, more preferably 1 or 2;    and-   R¹⁹ is carbonyl (—CO(R¹⁴)), carbonylthio (—C═O (SR¹⁴)), carbonyloxy    (—C═O (OR¹⁴)), oxycarbonyl (—OC═O (R¹⁴)), thiocarbonyl (—SC═O(R¹⁴)),    OH, halogen, halogen-substituted C₁-C₂₀-alkyl, pseudohalogen    radicals, amido (—C═O (NR¹⁴), phosphonate (—P(O) (OR¹⁴)₂), phosphate    (—OP(O) (OR¹⁴)₂), phosphine oxide (—P(O)R¹⁴R¹⁵), sulfonyl    (—S(O)₂R¹⁴), sulfonate (—S(O)₂OR¹⁴), sulfate (—OS(O)₂OR¹⁴),    sulfoxide (—S(O)R¹⁴), sulfonamide (—S(O)₂NR¹⁴R¹⁵), NO₂, boronic    esters (—OB(OR¹⁴)₂, imino (—C═NR¹⁴R¹⁵)) hydrazone radicals, oxime    radicals, nitroso groups, diazo groups, sulfoximines, SiR¹⁴R¹⁵R¹⁶,    and borane radicals, stannane radicals, acceptor-substituted vinyl    groups, boroxines and borazines, where R¹⁴, R¹⁵ and R¹⁶ are each    substituted or unsubstituted C₁-C₂₀-alkyl, preferably substituted or    unsubstituted C₁-C₆-alkyl, or substituted or unsubstituted    C₆-C₃₀-aryl, preferably substituted or unsubstituted C₆-C₁₀-aryl;    preferably halogen, preferably F, halogen-substituted alkyl,    preferably CF₃, CH₂F, CHF₂, C₂F₅, C₃F₃H₄, pseudohalogen, preferably    CN, carbonyloxy (—C═O (OR¹⁴)), preferably —C═O (OCH₃), phosphine    oxide, preferably P(O)Ph₂, and sulfonyl, preferably S(O)₂Ph₂;    -   or R¹⁹ is substituted or unsubstituted electron-deficient        heteroaryl having from five to 30 ring atoms, preferably        selected from the group consisting of pyridine, pyrimidine and        triazine.

More preferably, the compounds of the formula (II) used in theaforementioned layers have at least one R¹, R², R³, R⁴, R⁵, R⁶ or R⁷radical, selected from the group consisting of:

Inventive Compounds of the Formula (II)

In a further embodiment, the present invention relates to compounds ofthe general formula (II) as defined above, where, in the case that X isNR¹, at least one of the R¹ to R⁷, R^(a) or R^(b) radicals in thecompounds of the formula (II) comprises at least one heteroatom.

The compounds are preferably those of the general formula II

in which:

-   X is NR¹, S, O, PR¹, SO₂ or SO;-   R¹ is substituted or unsubstituted C₁-C₂₀-alkyl, substituted or    unsubstituted C₆-C₃₀-aryl, or substituted or unsubstituted    heteroaryl having from 5 to 30 ring atoms;-   R², R³, R⁴, R⁵, R⁶, R⁷    -   are each independently substituted or unsubstituted        C₁-C₂₀-alkyl, or substituted or unsubstituted C₆-C₃₀-aryl, or a        structure of the general formula (c)

-   R^(a), R^(b)    -   are each independently substituted or unsubstituted        C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, or        substituted or unsubstituted heteroaryl having from 5 to 30 ring        atoms or a substituent with donor or acceptor action selected        from the group consisting of: C₁-C₂₀-alkoxy, C₆-C₃₀-aryloxy,        C₁-C₂₀-alkylthio, C₆-C₃₀-arylthio, SiR¹⁴R¹⁵R¹⁶, halogen        radicals, halogenated C₁-C₂₀-alkyl radicals, carbonyl        (—CO(R¹⁴)), carbonylthio (—C═O (SR¹⁴)), carbonyloxy        (—C═O(OR¹⁴)), oxycarbonyl (—OC═O(R¹⁴)), thiocarbonyl        (—SC═O(R¹⁴)), amino (—NR¹⁴R¹⁵), OH, pseudohalogen radicals,        amido (—C═O (NR¹⁴)), —NR¹⁴C═O (R¹⁵), phosphonate (—P(O)        (OR¹⁴)₂), phosphate (—OP(O) (OR¹⁴)₂), phosphine (—PR¹⁴R¹⁵),        phosphine oxide (—P(O)R¹⁴ ₂), sulfate (—OS(O)₂OR¹⁴), sulfoxide        (—S(O)R¹⁴), sulfonate (—S(O)₂OR¹⁴), sulfonyl (—S(O)₂R¹⁴),        sulfonamide (—S(O)₂NR¹⁴R¹⁵), NO₂, boronic esters (—OB(OR¹⁴)₂),        imino (—C═NR¹⁴R¹⁵)), borane radicals, stannane radicals,        hydrazine radicals, hydrazone radicals, oxime radicals, nitroso        groups, diazo groups, vinyl groups, sulfoximines, alanes,        germanes, boroximes and borazines;-   R¹⁴, R¹⁵, R¹⁶    -   are each independently substituted or unsubstituted        C₁-C₂₀-alkyl, or substituted or unsubstituted C₆-C₃₀-aryl;-   q, r are each independently 0, 1, 2 or 3; where, in the case when q    or r is 0, all substitutable positions of the aryl radical are    substituted by hydrogen,    where the radicals and indices in the group of the formula (c) X′″,    R^(5′″), R^(6′″), R^(7′″), R^(a′″), R^(b′″), q′″ and r′″ are each    independently as defined for the radicals and indices of the    compounds of the general formula (II) X, R⁵, R⁶, R⁷, R^(a), R^(b), q    and r;    where,    in the case that X is NR¹, at least one of the R¹ to R⁷, R^(a) or    R^(b) radicals in the compounds of the formula (II) comprises at    least one heteroatom.

In the compounds of the formula (II), preferably at least one of the R²,R³ and R⁴ radicals and/or at least one of the R⁵, R⁶ and R⁷ radicals issubstituted or unsubstituted C₆-C₃₀-aryl.

The compound of the general formula (II) is more preferably a3,6-disilyl-substituted compound of the general formula (IIa):

in which:

-   X is NR¹, S, O, PR¹, SO₂ or SO; preferably NR¹, S or O; more    preferably NR¹;-   R¹ is substituted or unsubstituted C₁-C₂₀-alkyl, substituted or    unsubstituted C₆-C₃₀-aryl, or substituted or unsubstituted    heteroaryl having from 5 to 30 ring atoms; preferably substituted or    unsubstituted C₆-C₃₀-aryl or substituted or unsubstituted    C₁-C₂₀-alkyl, more preferably substituted or unsubstituted    C₆-C₁₀-aryl or unsubstituted C₁-C₂₀-alkyl, most preferably    substituted or unsubstituted phenyl;-   R², R³, R⁴, R⁵, R⁶, R⁷    -   are each independently substituted or unsubstituted C₁-C₂₀-alkyl        or substituted or unsubstituted C₆-C₃₀-aryl or a structure of        the general formula (c);    -   preferably at least one of the R², R³ and R⁴ radicals and/or at        least one of the R⁵, R⁶ and R⁷ radicals is substituted or        unsubstituted C₆-C₃₀-aryl, more preferably substituted or        unsubstituted C₆-C₁₀-aryl, most preferably substituted or        unsubstituted phenyl, and/or one of the R², R³ and R⁴ radicals        and/or one of the R⁵, R⁶ and R⁷ radicals is a radical of the        structure (c);-   R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³    -   are each independently hydrogen or are as defined for R^(a) and        R^(b), i.e. are each independently substituted or unsubstituted        C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₂₀-aryl,        substituted or unsubstituted heteroaryl having from 5 to 30 ring        atoms or a substituent with donor or acceptor action, suitable        substituents with donor or acceptor action having been specified        above; preferably hydrogen, substituted or unsubstituted        C₁-C₆-alkyl, substituted or unsubstituted C₆-C₁₀-aryl or        siR¹⁴R¹⁵R¹⁶; more preferably hydrogen, methyl, ethyl, phenyl,        CF₃ or siR¹⁴R¹⁵R¹⁶, where R¹⁴, R¹⁵ and R¹⁶ are preferably each        independently substituted or unsubstituted C₁-C₂₀-alkyl or        substituted or unsubstituted phenyl; more preferably, at least        one of the R¹⁴, R¹⁵ and R¹⁶ radicals is substituted or        unsubstituted phenyl; most preferably, at least one of the R¹⁴,        R¹⁵ and R¹⁶ radicals is substituted phenyl.

In the compounds of the formula (II), the R¹ radical and/or at least oneof the radicals from the group of R², R³ and R⁴ and/or at least one ofthe radicals from the group of R⁵, R⁶ and R⁷ are preferably eachindependently substituted or unsubstituted C₆-aryl of the followingformula:

in which

-   p is 0, 1, 2, 3, 4 or 5, preferably 0, 1, 2 or 3, more preferably 0,    1 or 2;-   R¹⁷ is hydrogen, substituted or unsubstituted C₁-C₂₀-alkyl,    substituted or unsubstituted C₆-C₃₀-aryl, substituted or    unsubstituted heteroaryl having from 5 to 30 ring atoms, a    substituent with donor or acceptor action,    -   or    -   a radical of the general formula a or b

in which

X′ is N or P, and

the radicals and indices X″, R^(2′), R^(3′), R^(4′), R^(5′), R^(5″),R^(6′), R^(6″), R^(7′), R^(7″), R^(a′), R^(a″), R^(b′), R^(b″), q′, q″,r′ and r″ are each independently as defined for the radicals and indicesX, R², R³, R⁴, R⁵, R⁶, R⁷, R^(a), R^(b), q and r;orone of the R², R³ and R⁴ radicals and/or one of the R⁵, R⁶ and R⁷radicals is a radical of the general formula c

in which the radicals and indices X′″, R^(5′″), R^(6′″), R^(7′″),R^(a′″), R^(b′″), q′″ and r′″ are each independently as defined for theradicals and indices X, R⁵, R⁶, R⁷, R^(a), R^(b), q and r.

Particularly preferred compounds of the formula (II) correspond to theaforementioned compounds of the formula (II) used with preference in theinventive OLEDs, where, in the case that X is NR¹, at least one of theR¹ to R⁷, R^(a) or R^(b) radicals in the compounds of the formula (II)comprises at least one heteroatom.

Preparation of the Inventive Compounds of the Formula (II) and ThoseUsed in Accordance with the Invention

The compounds of the formula (II) can in principle be prepared byprocesses known to those skilled in the art; for example, carbazoles ofthe formula (II) (X═NR¹) can be prepared thermally or photochemically byoxidative ring closure from diphenylamine (or suitably substitutedderivatives thereof) and, if appropriate, subsequent substitution, forexample on the nitrogen. In addition, the carbazoles of the formula (II)can be obtained proceeding from the suitably substitutedtetrahydrocarbazoles by oxidation. A typical carbazole synthesis is theBorsche-Drechsel cyclization (Borsche, Ann., 359, 49 (1908); Drechsel,J. prakt. Chem., [2], 38, 69, 1888). The aforementionedtetrahydrocarbozoles can be prepared by processes known to those skilledin the art, for example by condensation of, if appropriate, suitablysubstituted phenylhydrazine with, if appropriate, suitably substitutedcyclohexanone to obtain the corresponding imine. In a subsequent step,an acid-catalyzed rearrangement and ring closure reaction is effected toobtain the corresponding tetrahydrocarbazole. It is likewise possible tocarry out the preparation of the imine and the rearrangement and ringclosure reaction in one step. The imine is—as mentioned above—oxidizedto the desired carbazole.

The compounds of the formula (II) are prepared preferably proceedingfrom the corresponding base structure of the formula (III):

where X is NR¹, SO, SO₂, S, O or PR¹ or NH or PH or PPh. Suitable basestructures of the formula (III) are either commercially available(especially in the cases when X is SO₂, S, O, NH or PPh) or can beprepared by processes known to those skilled in the art (X═PH or SO).

In the case that X is NH or PH, the R¹ radicals may be introduced beforeor after the introduction of the R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷radicals, provided that the R^(a) and R^(b) radicals are present in thecompounds of the formula (II) or precursor compounds suitable forintroducing the R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals. Thus,three variants—in the case that X═NR¹ and PR¹—are possible:

Variant a)

-   ia) preparing a precursor compound suitable for introducing the    R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iia) introducing the R¹ radical,-   iiia) introducing the R^(a), R^(b) radicals, where present, and the    SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals.

Variant b)

Variant b) is preferred especially when R¹ is substituted orunsubstituted C₁-C₂₀-alkyl or C₆-C₃₀-aryl or C₁-C₂₀-alkyl-substitutedC₆-C₃₀-aryl.

-   ib) introducing the R¹ radical,-   iib) preparing a precursor compound suitable for introducing the    R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iiib) introducing the R^(a), R^(b) radicals, where present, and the    SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals.

Variant c)

-   ic) preparing a precursor compound suitable for introducing the    R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iic) introducing the R^(a), R^(b) radicals, where present, and the    SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iiic) introducing the R¹ radical.

In the case that X in formula (III) is NR¹, SO, SO₂, S, O or PR¹, thestep of “introducing the R¹ radical” is dispensed with, such that theprocess comprises the following steps (Variant d):

-   id) preparing a precursor compound suitable for introducing the    R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iid) introducing the R^(a), R^(b) radicals, where present, and the    SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals.

In a further embodiment, the present invention therefore relates to aprocess for preparing the inventive compounds of the formula (II) andthose used in accordance with the invention, comprising the steps of

proceeding from a base structure of the formula (III):

where X is NR¹, SO, SO₂, S, O or PR¹ or NH or PH or PPh, the R¹, R^(a),R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals, when the R^(a) and R^(b) radicalsare present in the compounds of the formula (II), are introduced by oneof the following variants a), b), c) or d),

Variant a)

-   ia) preparing a precursor compound suitable for introducing the    R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iia) introducing the R¹ radical,-   iiia) introducing the R^(a), R^(b) radicals, where present, and the    SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals;    or

Variant b)

-   ib) introducing the R¹ radical,-   iib) preparing a precursor compound suitable for introducing the    R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iiib) introducing the R^(a), R^(b) radicals, where present, and the    SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals;    or

Variant c)

-   ic) preparing a precursor compound suitable for introducing the    R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iic) introducing the R^(a), R^(b) radicals, where present, and the    SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iiic) introducing the R¹ radical;    or

Variant d)

-   id) preparing a precursor compound suitable for introducing the    R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals,-   iid) introducing the R^(a), R^(b) radicals, where present, and the    SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals.

Radicals and groups q, r, R¹, R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷specified in the compounds of the formula (II) have each been definedabove.

Steps ia), ic) and id)

Suitable precursor compounds for introducing the R^(a), R^(b), SiR²R³R⁴and SiR⁵R⁶R⁷ radicals are especially the corresponding halogenated,preferably brominated, compounds of the general formula (IV):

where Hal is halogen, preferably bromine or iodine, more preferablybromine, n is in each case 0, 1 or 2 (where the sum of the two n informula (IV) is at least 1), preferably in each case 1, and X in stepsia) and ic) is NH or PH, X in step ib) is NR¹ or PR¹, and X in step id)is NR¹, SO, SO₂, S, O or PR¹.

The halogenation can be carried out by processes known to those skilledin the art. Preference is given to brominating or iodinating in the 3and 6 position of the base structure of the formula (III).

Particular preference is given to brominating with Br₂ in glacial aceticacid or chloroform at low temperatures, for example 0° C. Suitableprocesses are, for example, described in M. Park, J. R. Buck, C. J.Rizzo, Tetrahedron, 1998, 54, 12707-12714 for X═NPh, and in W. Yang etal., J. Mater. Chem. 2003, 13, 1351 for X═S. In addition, somebrominated products of the formula (IV) are commercially available (forX═NH and S).

Steps iia), ib) and iiic)

The R¹ radical is introduced by processes known to those skilled in theart.

The radical is introduced preferably by reacting the base structure ofthe formula (III) or the compound of the formula (IV) with an alkylhalide or aryl halide or heteroaryl halide of the formula R¹-Hal whereR¹ has already been defined above and Hal is F, Cl, Br or I, preferablyBr, I or F.

The introduction of the R¹ radical is generally carried out in thepresence of a base. Suitable bases are known to those skilled in the artand are preferably selected from the group consisting of alkali metaland alkaline earth metal hydroxides such as NaOH, KOH, Ca(OH)₂, alkalimetal hydrides such as NaH, KH, alkali metal amides such as NaNH₂,alkali metal or alkaline earth metal carbonates such as K₂CO₃ or Cs₂CO₃,and alkali metal alkoxides such as NaOMe, NaOEt. Additionally suitableare mixtures of the aforementioned bases. Particular preference is givento NaOH, KOH, NaH or K₂CO₃.

The N-alkylation (for example disclosed in M. Tosa et al., Heterocycl.Communications, Vol. 7, No. 3, 2001, p. 277-282) or N-arylation orN-heteroarylation (for example (N-arylation) disclosed in H. Gilman andD. A. Shirley, J. Am. Chem. Soc. 66 (1944) 888; D. Li et al., Dyes andPigments 49 (2001) 181-186) is preferably carried out in a solvent.Suitable solvents are, for example, polar aprotic solvents such asdimethyl sulfoxide, dimethylformamide or alcohols. It is likewisepossible to use an excess of the alkyl halide or (hetero)aryl halideused as the solvent. The reaction can additionally be performed in anonpolar aprotic solvent, for example toluene, when a phase transfercatalyst, for example tetra-n-butylammonium hydrogensulfate, is present(as disclosed, for example, in I. Gozlan et al., J. Heterocycl. Chem. 21(1984) 613-614).

The N-(hetero)arylation can, for example, be effected bycopper-catalyzed coupling of the compound of the formula (III) or (IV)to a (hetero)aryl halide, for example an aryl iodide (Ullmann reaction).

Preference is given to introducing the R¹ radical by reacting thecompound of the formula (III) or (IV) with an alkyl fluoride, arylfluoride or heteroaryl fluoride in the presence of NaH in DMF(nucleophilic substitution), or by reaction with an alkyl bromide oriodide, aryl bromide or iodide or heteroaryl bromide or iodide underCu/base (Ullmann, see above) or Pd catalysis.

The molar ratio of the compound of the formula (III) or (IV) to thealkyl halide or (hetero)aryl halide of the formula R¹-Hal is generallyfrom 1:1 to 1:15, preferably from 1:1 to 1:6, more preferably 1:4.

The N-alkylation or N-(hetero)arylation is performed generally at atemperature of from 0 to 220° C., preferably from 20 to 200° C. Thereaction time is generally from 0.5 to 48 h, preferably from 1 to 24 h.In general, the N-alkylation or N-arylation is performed at standardpressure.

The resulting crude product is worked up by processes known to thoseskilled in the art.

Preferred embodiments of steps iia), ib) and iiic) are detailedhereinafter in general form using the example of R¹=substituted phenyl(R=aforementioned substituent on the aryl radical; q=0, 1, 2, 3, 4 or5):

Steps iiia), iiib), iic) and iid)

The desired silylated compounds of the formula (II) are preparedproceeding from the halogenated precursor compounds of the formula (IV)generally by halogen/metal exchange and subsequent silylation byprocesses known to those skilled in the art.

Preference is given to effecting the preparation, in a first step, byhalogen/metal exchange by reaction of the halogenated compounds of theformula (IV) with alkyllithium compounds or Mg at temperatures ofgenerally from −80° C. to +80° C., preferably at from −78° C. to 0° C.(for alkyllithium compounds) or from 0° C. to 80° C. (for Mg), morepreferably from 0° C. to 40° C. (for Mg). Particular preference is givento using alkyllithium compounds, especially n-BuLi or tert-BuLi. Thereaction is effected generally in a solvent, preferably in THF (orether, preferably diethyl ether). In a directly subsequent second step,a silylation is effected to give the desired compounds of the formula(II), preferably by reaction with SiR_(m)Cl_((4-m)) orSiR_(m)(OR′)_((4-m)), where m is 1, 2 or 3 and R′ is C₁- to C₆-alkyl.The silylation is generally carried out in a solvent. Preferred solventsare THF or ethers, preferably diethyl ether. In general, the silylationis effected directly after the reaction in the first step, withoutworkup or isolation of the product obtained after the first step. Thehalogen/metal exchange and the subsequent silylation are generallyrepeated sufficient times for all n halogen radicals in the compound ofthe formula (IV) to be replaced by silyl groups. Tsai et al., Adv.Mater., 2006, Vol. 18, No. 9, pages 1216 to 1220.

In the case when the halogen/metal exchange and the subsequentsilylation are performed on a compound of the formula (IV) in which X═NHor PH (variant c), step iic)), it is necessary to protect the NH or PHgroup by means of a protecting group and to deprotect again after thesilylation.

The protecting group is introduced by processes known to those skilledin the art. In general, initial deprotonation is followed byintroduction of a protecting group. Suitable N—H and P—H protectinggroups are known to those skilled in the art, and silyl protectinggroups, especially SiR₃ where R=alkyl or aryl, preferably methyl, ethyl,phenyl, are particularly suitable for this process. The deprotonation iseffected typically with bases, for example with NaH, nBuLi or tert-BuLi.

The deprotection is likewise effected by processes known to thoseskilled in the art. Suitable reagents for deprotection are guided by theprotecting groups used. When SiR₃ is used as the protecting group, thedeprotection is effected generally with an acid or TBAF(tetrabutylammonium fluoride).

Preferred embodiments of steps iiia), iiib) and iid) are shown below ingeneral form (X═NR¹, SO, SO₂, S, O or PR¹):

When p=1 or 2, step 1 and 2 can be repeated once again until p=0.

In step iic) (X═NH or PH), the halogen/metal exchange with subsequentsilylation is generally preceded by the introduction of a protectinggroup. A preferred embodiment of step iic) is shown below using theexample of X═NH:

Carbene Complex of the Formula (I) Used in the Inventive OrganicLight-Emitting Diode

According to the invention, the organic light-emitting diode, as well asat least one compound of the formula (II), comprises at least onecarbene complex of the general formula (I)

in which the symbols are each defined as follows:

-   M¹ is a metal atom selected from the group consisting of transition    metals of group IB, IIB, IIIB, IVB, VB, VIIB, VIIB, VIII, the    lanthanides and IIIA of the Periodic Table of the Elements (CAS    version) in any oxidation state possible for the particular metal    atom, preferred metal atoms already having been specified above;-   carbene is a carbene ligand which may be uncharged or monoanionic    and mono-, bi- or tridentate; the carbene ligand may also be a bis-    or triscarbene ligand;-   L is a mono- or dianionic ligand, preferably monoanionic ligand,    which may be mono- or bidentate;-   K is an uncharged mono- or bidentate ligand;-   n is the number of carbene ligands, where n is at least 1,    preferably from 1 to 6, and the carbene ligands in the complex of    the formula I, when n>1, may be the same or different;-   m is the number of ligands L, where m may be 0 or 1, preferably from    0 to 5, and the ligands L, when m>1, may be the same or different;-   o is the number of ligands K, where o may be 0 or 1, preferably from    0 to 5, and the ligands K, when o>1, may be the same or different;-   p is the charge of the complex: 0, 1, 2, 3 or 4;-   W is a monoanionic counterion.

Suitable carbene complexes of the formula (I) used with preference arespecified in WO 2005/019373, WO 2005/113704, WO 06/018292, WO 06/056418and also European applications 06112198.4, 06112228.9, 06116100.6 and06116093.3, which were yet to be published at the priority date of thepresent application. Particularly preferred carbene complexes arespecified in WO 05/019373 and WO 06/056148.

The disclosure content of the WO and EP applications cited is referredto explicitly here, and these disclosures shall be considered to beincorporated into the content of the present application. In particular,suitable carbene complexes of the formula (I) for use in the inventiveOLEDs comprise carbene ligands of the following structures disclosed,inter alia, in WO 2005/019373 A2 (the designation of the variables usedhereinafter was adopted from the application WO 2005/019373 A2; withregard to the more specific definition of the variables, reference ismade explicitly to this application):

in which:

-   * denotes the attachment sites of the ligand to the metal center;-   z, z′ are the same or different and are each CH or N;-   R¹², R^(12′) are the same or different and are each an alkyl, aryl,    heteroaryl or alkenyl radical, preferably an alkyl or aryl radical,    or in each case 2 R¹² or R^(12′) radicals together form a fused ring    which may optionally comprise at least one heteroatom, preferably N;    preferably in each case 2 R¹² or R^(12′) radicals together form a    fused aromatic C₆ ring, where one or more further aromatic rings may    optionally be fused to this preferably six-membered aromatic ring,    any conceivable fusion being possible, and the fused radicals may in    turn be substituted; or R¹² or R^(12′) is a radical with donor or    acceptor action, preferably selected from the group consisting of    halogen radicals, preferably F, Cl, Br, more preferably F; alkoxy,    aryloxy, carbonyl, ester, amino groups, amide radicals, CHF₂, CH₂F,    CF₃, CN, thio groups and SCN;-   t and t′ are the same or different, preferably the same, and are    each from 0 to 3, where, when t or t′ is >1, the R¹² or R^(12′)    radicals may be the same or different; t or t′ is preferably 0 or 1;    the R¹² or R^(12′) radical is, when t or t′ is 1, in the ortho-,    meta- or para-position to the bonding site to the nitrogen atom    adjacent to the carbene carbon atom;-   R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹¹ are each hydrogen, alkyl, aryl,    heteroaryl, alkenyl or a substituent with donor or acceptor action,    preferably selected from halogen radicals, preferably F, Cl, Br,    more preferably F, alkoxy radicals, aryloxy radicals, carbonyl    radicals, ester radicals, amine radicals, amide radicals, CH₂F    groups, CHF₂ groups, CF₃ groups, CN groups, thio groups and SCN    groups, preferably hydrogen, alkyl, heteroaryl or aryl,-   R¹⁰ is alkyl, aryl, heteroaryl or alkenyl, preferably alkyl,    heteroaryl or aryl, or in each case 2 R¹⁰ radicals together form a    fused ring which may optionally comprise at least one heteroatom,    preferably nitrogen; preferably in each case 2 R¹⁰ radicals together    form a fused aromatic C₆ ring, where one or more further aromatic    rings may optionally be fused to this preferably six-membered    aromatic ring, any conceivable fusion being possible, and the fused    radicals may in turn be substituted; or R¹⁰ is a radical with donor    or acceptor action, preferably selected from the group consisting of    halogen radicals, preferably F, Cl, Br, more preferably F; alkoxy,    aryloxy, carbonyl, ester, amino groups, amide radicals, CHF₂, CH₂F,    CF₃, CN, thio groups and SCN-   v is from 0 to 4, preferably 0, 1 or 2, most preferably 0, where,    when v is 0, the four carbon atoms of the aryl radical in formula c,    which are optionally substituted by R¹⁰, bear hydrogen atoms.

Especially suitable carbene complexes of the formula (I) for use in theinventive OLEDs are Ir-carbene complexes of the following structuresdisclosed in WO 2005/019373 A2:

where the variables are each as already defined above.

Further suitable carbene complexes of the formula (I) are especiallyalso structures disclosed in WO 2006/056418 A2 (the designation of thevariables used hereinafter was adopted from the application WO2006/056418 A2; with regard to the more exact definition of thevariables, reference is made explicitly to this application):

in which M is Ru(III), Rh(III), Ir(III), Pd(II) or Pt(II), n assumes thevalue of 3 for Ru(III), Rh(III) and Ir(III), and the value of 2 forPd(II) and Pt(II), and Y² and Y³ are each hydrogen, methyl, ethyl,n-propyl, isopropyl or tert-butyl. M is preferably Ir(III) with n equalto 3. Y³ is preferably methyl, ethyl, n-propyl, isopropyl or tert-butyl.

Further suitable carbene complexes of the formula (I) are especiallyalso

in which M is Ru(III), Rh(III), Ir(III), Pd(II) or Pt(II), n assumes thevalue of 3 for Ru(III), Rh(III) and Ir(III), and the value of 2 forPd(II) and Pt(II), and Y³ is hydrogen, methyl, ethyl, n-propyl,isopropyl or tert-butyl. M is preferably Ir(III) with n equal to 3. Y³is preferably methyl, ethyl, n-propyl, isopropyl or tert-butyl.

Further suitable carbene complexes of the formula (I) are especiallyalso:

in which M is Ru(III), Rh(III) and especially Ir(III), Pd(II) or Pt(II),n assumes the value of 3 for Ru(III), Rh(III) and Ir(III), and the valueof 2 for Pd(II) and Pt(II).

Further suitable carbene complexes of the formula (I) are especiallyalso:

in which M is Ru(III), Rh(III) and especially Ir(III), Pd(II) or Pt(II),n assumes the value of 3 for Ru(III), Rh(III) and Ir(III), and the valueof 2 for Pd(II) and Pt(II).

In addition, complexes with different carbene ligands and/or with mono-or dianionic ligands, which may be either mono- or bidentate, are alsouseful.

With reference to the table which follows, complexes ML′(L″)₂ withtrivalent metal centers and two different carbene ligands L′ and L″ arespecified schematically.

L′ L″ L′ L″ L′ L″ L′ L″ L¹ L² L³ L⁴ L⁷ L⁵ L⁵ L³ L¹ L³ L³ L⁵ L⁷ L⁴ L⁵ L²L¹ L⁴ L³ L⁶ L⁷ L³ L⁵ L¹ L¹ L⁵ L³ L⁷ L⁷ L² L⁴ L³ L¹ L⁶ L⁴ L⁵ L⁷ L¹ L⁴ L²L¹ L⁷ L⁴ L⁶ L⁶ L⁵ L⁴ L¹ L² L³ L⁴ L⁷ L⁶ L⁴ L³ L² L² L⁴ L⁵ L⁶ L⁶ L³ L³ L¹L² L⁵ L⁵ L⁷ L⁶ L² L² L¹ L² L⁶ L⁶ L⁷ L⁶ L¹ L² L⁷ L⁷ L⁶ L⁵ L⁴where M is, for example, Ru(III), Rh(III) or Ir(III), especiallyIr(III), and L′ and L″ are, for example, ligands selected from the groupof ligands L¹ to L⁷

Y² is hydrogen, methyl, ethyl, n-propyl, isopropyl or tert-butyl, and Y³is methyl, ethyl, n-propyl, isopropyl or tert-butyl.

One representative of these complexes with different carbene ligands(L′=L⁴ when Y²=hydrogen and Y³=methyl; L″=L² when Y²=hydrogen andY³=methyl) is, for example:

It will be appreciated that, in the carbene complexes of trivalent metalcenters (for instance in the case of Ru(III), Rh(III) or Ir(III)), allthree carbene ligands in the carbene complexes of the formula (I) mayalso be different from one another.

Examples of complexes of trivalent metal centers M with ligands L (heremonoanionic bidentate ligand) as “spectator ligands” are LM′L″, LM(L′)₂and L₂ML′, in which M is, for instance, Ru(III), Rh(III) or Ir(III),especially Ir(III), and L′ and L″ are each as defined above. For thecombination of L′ and L″ in the complexes LML′L″, this gives rise to:

L′ L″ L¹ L² L¹ L³ L¹ L⁴ L¹ L⁵ L¹ L⁶ L¹ L⁷ L² L³ L² L⁴ L² L⁵ L² L⁶ L² L⁷L³ L⁴ L³ L⁵ L³ L⁶ L³ L⁷ L⁴ L⁵ L⁴ L⁶ L⁴ L⁷ L⁵ L⁶ L⁵ L⁷ L⁶ L⁷

Useful ligands L are in particular acetylacetonate and derivativesthereof, picolinate, Schiff bases, amino acids and the bidentatemonoanionic ligands specified in WO 02/15645 A1; in particular,acetylacetonate and picolinate are of interest. In the case of thecomplexes L₂ML′, the ligands L may be the same or different.

One representative of these complexes with different carbene ligands(L′=L⁴ when Y²=hydrogen and Y³=methyl; L″=L² when Y²=hydrogen andY³=methyl) is, for example:

in which z¹ and z² in the symbol

represent the two “teeth” of the ligand L. Y³ is hydrogen, methyl,ethyl, n-propyl, isopropyl or tert-butyl, especially methyl, ethyl,n-propyl or isopropyl.

Further suitable carbene complexes of the formula (I) are:

in which R is hydrogen, alkyl or aryl, preferably methyl, ethyl,n-propyl, isopropyl, tert-butyl or phenyl,and also

in which M is Ru(III), Rh(III), Ir(III), Pd(II) or Pt(II), n assumes thevalue of 3 in the case that M is Ru(III), Rh(III) and Ir(III), andassumes the value of 2 in the case that M is Pd(II) and Pt(II), and Y²and Y³ are each hydrogen, methyl, ethyl, n-propyl, isopropyl ortert-butyl. M is preferably Ir(III) with n equal to 3. Y³ is preferablymethyl, ethyl, n-propyl, isopropyl or tert-butyl.

In addition, the following specific carbene complexes of the formula (I)are suitable for use in the inventive OLEDs:

The aforementioned carbene complexes are prepared by processes known tothose skilled in the art. The stoichiometries and reaction conditionscan be determined without any problem by the person skilled in the arton the basis of the aforementioned patent applications relating tocarbene complexes and their preparation processes. In addition, theexample part of the present application comprises references todocuments in which processes for preparing some of the aforementionedcarbene complexes are disclosed. The carbene complexes which are notdescribed explicitly in the examples may be prepared in analogy to theprocesses described in the example part.

Use of the inventive compounds of the formula (II) as matrix materialsin the light-emitting layer and/or in at least one further layer of theinventive OLEDs allows OLEDs with high efficiency and lifetime to beobtained. The efficiency of the inventive OLEDs can additionally beimproved by optimizing the other layers. For example, highly efficientcathodes such as Ca or Ba, if appropriate in combination with anintermediate layer of LiF, can be used. Shaped substrates and novelhole-transporting materials which bring about a reduction in theoperating voltage or an increase in the quantum efficiency can likewisebe used in the inventive OLEDs. In addition, additional layers may bepresent in the OLEDs in order to adjust the energy level of thedifferent layers and in order to facilitate electroluminescence.

The inventive OLEDs can be used in all devices in whichelectroluminescence is useful. Suitable devices are preferably selectedfrom stationary and mobile visual display units and illumination units.Stationary visual display units are, for example, visual display unitsof computers, televisions, visual display units in printers, kitchenappliances and advertising panels, illuminations and information panels.Mobile visual display units are, for example, visual display units incellphones, laptops, digital cameras, vehicles and destination displayson buses and trains.

In addition, the compounds of the formula (II) can be used together withthe carbene complex of the formula (I) in OLEDs with inverse structure.Preference is given to using the compounds of the formula (II) used inaccordance with the invention in these inverse OLEDs, in turn, as matrixmaterials in the light-emitting layer together with at least one carbenecomplex of the formula (I) and/or in at least one further layer of theOLED. The structure of inverse OLEDs and the materials customarily usedtherein are known to those skilled in the art.

The present invention further relates to a light-emitting layercomprising at least one compound of the formula (II) according to thepresent invention and at least one carbene complex of the generalformula (I) according to the present invention. Preferred compounds ofthe formula (II) and carbene complexes of the formula (I) are specifiedabove.

In general, the proportion of the at least one compound of the formula(II) in the light-emitting layer of the inventive OLED is from 10 to 99%by weight, preferably from 50 to 99% by weight, more preferably from 70to 97% by weight. The proportion of the at least one carbene complex ofthe general formula (I) as an emitter material in the light-emittinglayer is generally from 1 to 90% by weight, preferably from 1 to 50% byweight, more preferably from 3 to 30% by weight, where the proportionsof the at least one compound of the formula (II) and the at least onecarbene complex of the general formula (I) used as an emitter compoundadd up to 100% by weight. However, it is also possible that thelight-emitting layer, as well as the at least one compound of thegeneral formula (II) and the at least one carbene complex of the generalformula (I), comprises further substances, for example further diluentmaterial, further matrix material other than the compounds of theformula (II), further diluent material, for example, being specifiedbelow.

The present invention further provides for the use of compounds of thegeneral formula II according to the present application as matrixmaterial, hole/exciton blocker material and/or electron/exciton blockermaterial and/or hole injection material and/or electron injectionmaterial and/or hole conductor material and/or electron conductormaterial in an organic light-emitting diode which comprises at least onecarbene complex of the general formula I according to the presentapplication. Preference is given to using the compounds of the formula(II) as matrix materials and/or hole/exciton blocker materials in theinventive OLED.

Preferred compounds of the formula (II), preferred carbene complexes ofthe formula (I) and preferred embodiments relating to the use ofcompounds of the formula (II) which have particular substituents inspecific layers of the inventive OLEDs are specified above.

The present invention further relates to a device selected from thegroup consisting of stationary visual display units such as visualdisplay units of computers, televisions, visual display units inprinters, kitchen appliances and advertising panels, illuminations,information panels and mobile visual display units, such as visualdisplay units in cellphones, laptops, digital cameras, vehicles anddestination displays on buses and trains, and illumination unitscomprising at least one inventive organic light-emitting diode or atleast one inventive light-emitting layer.

The examples which follow provide additional illustration of theinvention.

A PREPARATION OF COMPOUNDS OF THE GENERAL FORMULA (II) Example 1Bromination of N-Substituted Carbazoles Example 1a Synthesis of9-(3,5-bis(trifluoromethyl)phenyl)-3,6-dibromocarbazole

A solution of 9-(3,5-bis(trifluoromethyl)phenyl)-9H-carbazole (2.7 g, 1eq) in glacial acetic acid (210 ml) is slowly admixed with a solution ofbromine (2.3 g, 2.0 eq) in glacial acetic acid (7 ml). After stirringfor 1 h, the mixture is admixed with ice-water (1000 ml) and stirred for1 h. The precipitate is filtered off and washed with water. The residueis recrystallized in ethyl acetate. Yield 55%. ¹H NMR (THF-d8, 400 MHz):δ=7.3 (d, 2H), 7.6 (d, 2H), 8.2 (s, 1H), 8.3 (s, 2H), 8.4 (s, 2H).

Example 1b Synthesis of 9-(3-cyanophenyl)-3,6-dibromocarbazole

A solution of 9-(3-cyanophenyl)-9H-carbazole (3.5 g, 1 eq) in glacialacetic acid (150 ml) is admixed slowly with a solution of bromine (4.1g, 2.0 eq) in glacial acetic acid (5 ml). After stirring for 3 h, themixture is admixed with ice-water (500 ml) and stirred for 1 h. Theprecipitate is filtered off and washed with water. The residue isrecrystallized in ethanol. Yield 69%. ¹H NMR (CDCl₃, 400 MHz): δ=7.2 (d,2H), 7.5 (d, 2H), 7.75 (m, 3H), 7.8 (s, 1H), 8.2 (s, 2H).

Example 2 N-Arylation of Carbazole (X in the General Formula III is N—H)

General Procedure:

Carbazole (1 eq), phenyl halide A, potassium carbonate and copper powderare heated to 160-200° C. and stirred overnight at this temperature.After cooling to room temperature, the mixture is extracted with acetoneor methylene chloride. The precipitate is filtered off and purified bycolumn chromatography (silica gel, methylene chloride/cyclohexane).

The table which follows summarizes the data of various N-arylations ofcarbazole which have been carried out according to the general method:

Equiv. A Equiv. K₂CO₃ Mol % Cu T (° C.) Yield Analysis

1.1 1.5 12 165 41 ¹H NMR (CDCl₃, 400 MHz): δ = 7.35 (m, 4H), 7.4 (m,2H), 7.9 (s, 1H), 8.1 (s, 2H), 8.2 (d, 2H). MALDI- MS: m/z = 379

1.1 1.2 12.5 180 76 ¹H NMR (CDCl₃, 400 MHz): δ = 3.8 (s, 6H), 6.6 (s,1H), 6.7 (s, 2H), 7.3 (dd, 2H), 7.4 (dd, 2H), 7.5 (d, 2H), 8.1 (d, 2H);MALDI-MS: m/z = 303

1.1 1.2 12.5 180- 200 73 ¹H NMR (CDCl₃, 400 MHz): δ = 3.8 (s, 6H), 3.9(s, 3H), 6.8 (s, 2H), 7.3 (m, 2H), 7.4 (virtually d, 4H), 8.2 (d, 2H).

1.1 1.2 12.5 175 73 ¹H NMR (CDCl₃, 400 MHz): δ = 7.3 (m, 4H), 7.45 (dd,2H), 7.7 (dd, 2H), 7.8 (dd, 1H), 7.9 (s, 1H), 8.2 (d, 2H).

Example 3 N-Arylation of Brominated Carbazole Derivatives (X in theGeneral Formula III is N—H)

procedure:

Carbazole (1 eq), phenyl iodide B, potassium carbonate and copper powderare heated to 130-160° C. and stirred at this temperature for 48 h.Cooling to room temperature is followed by extraction with methylenechloride. Recrystallization from EtOH gives the desired product.

The table which follows summarizes the data of various N-arylations ofbrominated carbazole derivatives which have been carried out accordingto the general procedure:

Equiv. B Equiv. K₂CO₃ Mol % Cu T (° C.) Yield Analysis

4 2.5 21 130 70 ¹H NMR (CDCl₃, 400 MHz): δ = 3.9 (s, 6H), 4.0 (s, 3H),6.6 (s, 2H), 7.2 (d, 2H), 7.5 (d, 2H), 8.2 (s, 2H).

2.9 2.6 18 125 68 ¹H NMR (CD₂Cl₂, 400 MHz): δ = 1.4 (s, 9H), 7.25 (d,2H), 7.37 (d, 2H), 7.47 (d, 2H), 7.6 (d, 2H), 8.2 (s, 2H).

2 1.25 11 130 60 ¹H NMR (CDCl₃, 400 MHz): δ = 3.9 (s, 3H), 7.1 (d, 2H),7.2 (d, 2H), 7.4 (d, 2H), 7.5 (d, 2H), 8.2 (s, 2H).

Example 4 Coupling of Brominated N-Arylated Carbazole Derivatives andBrominated Dibenzothiophene Derivatives with Silyl Compounds Example 4aSynthesis of 2,8-bis(triphenylsilyl)dibenzothiophene

A solution of 2,8-dibromodibenzothiophene (3.0 g, 1 eq) in dry THF (165ml) at −78° C. under argon is admixed slowly with n-butyllithium (1.6 Min hexane, 13.7 ml, 2.5 eq), and stirred at −78° C. for 1 h. Afteradding a solution of chlorotriphenylsilane (6.5 g, 2.5 eq) in dry THF(14 ml) at −78° C., the mixture is warmed to room temperature withstirring overnight. Excess butyllithium is hydrolyzed with saturatedammonium chloride solution. The precipitated product is filtered off andwashed thoroughly with THF, water and methyl tert-butyl ether. Thecombined THF filtrates are concentrated to dryness and stirred with alittle ethyl acetate. The precipitate is filtered off and purified bycolumn chromatography (silica gel, ethyl acetate/cyclohexane). Yield:46%. ¹H NMR (CD₂Cl₂, 400 MHz): δ=7.35-7.41 (m, 12H), 7.44-7.49 (m, 6H),7.55-7.59 (m, 12H), 7.65 (d, J=8.0, 2H), 7.92 (d, J=8.0, 2H), 8.16 (s,2H).

Example 4b Synthesis of 9-phenyl-3,6-bis(triphenylsilyl)carbazole

A solution of 9-phenyl-3,6-dibromo-9H-carbazole (6.0 g, 1 eq) in dry THF(500 ml) at −78° C. under argon is admixed slowly with n-butyllithium(1.6 M in hexane, 28.2 ml, 3.0 eq) and stirred at −78° C. for 1 h. Afteradding a solution of chlorotriphenylsilane (13.5 g, 3.0 eq) in dry THF(100 ml) at −78° C., the mixture is warmed to room temperature withstirring overnight. Excess butyllithium is hydrolyzed with saturatedammonium chloride solution. The precipitated product is filtered off andwashed thoroughly with CH₂Cl₂. The product precipitates out of thecombined CH₂Cl₂ filtrates. Yield: 40%. If the product does notprecipitate out, the combined CH₂Cl₂ filtrates are concentrated todryness. Recrystallization with ethyl acetate gives the product. ¹H NMR(CDCl₃, 400 MHz): δ=7.35 (m, 12H), 7.45 (m, 9H), 7.52-7.6 (m, 18H), 8.2(s, 2H).

Example 4c Synthesis of9-(3,4,5-trimethoxyphenyl)-3,6-bis(triphenylsilyl)carbazole

A solution of 9-(3,4,5-trimethoxyphenyl)-3,6-dibromo-9H-carbazole (1.5g, 1 eq) in dry THF (100 ml) at −78° C. under argon is admixed slowlywith n-butyllithium (1.6 M in hexane, 5.6 ml, 3.0 eq) and stirred at−78° C. for 1 h. After adding a solution of chlorotriphenylsilane (2.7g, 3.0 eq) in dry THF (40 ml) at −78° C., the mixture is warmed to roomtemperature with stirring overnight. Excess butyllithium is hydrolyzedwith saturated ammonium chloride solution. The precipitated product isfiltered off and washed thoroughly with methylene chloride. The combinedmethylene chloride filtrates are concentrated to dryness. The solid isstirred in methanol and filtered off. Yield: 63%. ¹H NMR (CDCl₃, 400MHz): δ=3.8 (s, 6H), 3.9 (s, 3H), 6.75 (s, 2H), 7.3 (m, 12H), 7.4 (m,8H), 7.6 (m, 14H), 8.2 (s, 2H).

Example 4d Synthesis of3,6-bis[(3,5-bis(trifluoromethyl)phenyl)dimethylsilyl]-9-phenyl-carbazole

A solution of 9-phenyl-3,6-dibromo-9H-carbazole (1.3 g, 1 eq) in dry THF(50 ml) at −78° C. under argon is admixed slowly with n-butyllithium(1.6 M in hexane, 5.1 ml, 2.5 eq) and stirred at −78° C. for 1 h. Afteradding a solution of 3,5-bis(trifluoromethyl)phenyldimethylchlorosilane(2.5 g, 2.5 eq) in dry THF (20 ml) at −78° C., the mixture is warmed toroom temperature with stirring overnight. Excess butyllithium ishydrolyzed with saturated ammonium chloride solution. The precipitatedproduct is filtered off and washed thoroughly with CH₂Cl₂. The combinedmethylene chloride filtrates are extracted with water and concentratedto dryness. The residue is purified by column chromatography (silicagel, methylene chloride/cyclohexane). Yield 60%. ¹H NMR (CDCl₃, 400MHz): δ=0.7 (s, 12H), 7.4-7.7 (m, 9H), 7.8 (s, 2H), 8.0 (s, 4H), 8.3 (s,2H).

Example 4e Synthesis of3,6-bis[(4-methoxyphenyl)dimethylsilyl]-9-phenylcarbazole

A solution of 9-phenyl-3,6-dibromo-9H-carbazole (1.6 g, 1 eq) in dry THF(20 ml) at −78° C. under argon is admixed slowly with n-butyllithium(1.6 M in hexane, 6.1 ml, 2.5 eq) and stirred at −78° C. for 1 h. Afteradding a solution of 4-methoxyphenyl-dimethylchlorosilane (2.4 g, 3.1eq) in dry THF (10 ml) at −78° C., the mixture is warmed to roomtemperature with stirring overnight. Excess butyllithium is hydrolyzedwith saturated ammonium chloride solution. The precipitated product isfiltered off and washed thoroughly with CH₂Cl₂. The combined methylenechloride filtrates are extracted with water and concentrated to dryness.The residue is purified by column chromatography (silica gel,hexane/ethyl acetate). Yield 40%. MALDI-MS: m/z=571. HPLC: 99% purity.

Example 4f Synthesis of9-(3-methoxyphenyl)-3,6-bis(triphenylsilyl)carbazole

A solution of 9-(3-methoxyphenyl)-3,6-dibromo-9H-carbazole (2.5 g, 1 eq)in dry THF (100 ml) at −78° C. under argon is admixed slowly withn-butyllithium (1.6 M in hexane, 5.6 ml, 2.5 eq) and stirred at −78° C.for 1 h. After adding a solution of chlorotriphenylsilane (4.3 g, 2.5eq) in dry THF (40 ml) at −78° C., the mixture is warmed to roomtemperature with stirring overnight. Excess butyllithium is hydrolyzedwith saturated ammonium chloride solution. The precipitated product isfiltered off and washed thoroughly with methylene chloride. The combinedmethylene chloride filtrates are extracted with water and concentratedto dryness. The residue is purified by column chromatography (silicagel, cyclohexane/methylene chloride). Yield 41%. ¹H NMR (CDCl₃, 400MHz): δ=3.9 (s, 3H), 7.05 (d, 2H), 7.15 (m, 14H), 7.20 (m, 8H), 7.55 (d,2H), 7.60 (d, 12H), 8.2 (s, 2H).

Example 4g Synthesis of 2,8-bis(triphenylsilyl)dibenzofuran

Reaction Procedure:

6.02 g (18.47 mmol) of 2,8-dibromodibenzofuran are suspended in 120 mlof THF and admixed cautiously at −78° C. with 22.9 ml (36.64 mmol) ofn-BuLi (1.6M in hexane). Thereafter, the mixture is stirred at −78° C.for 3 h. The reaction mixture is admixed with a solution of 10.91 g(37.00 mmol) of chlorotriphenylsilane in 120 ml of THF, allowed to warmto room temperature and stirred at room temperature for 16 h. Themixture is quenched cautiously with 10 ml of methanol and thenconcentrated to dryness. The residue is digested first in methanol, thenin water and subsequently in methanol again, filtered off and dried. Thecrude product is dissolved in methylene chloride, filtered throughsilica gel and crystallized by blanketing with cyclohexane. The crystalsare filtered off and dried. 9.28 g (73%) of white powder are obtained.

¹H NMR: (CD₂Cl₂, 500 MHz):

δ=7.35-7.38 (m, 12H, CH_(Ar)), 7.41-7.44 (m, 6H, CH_(Ar)), 7.56-7.57 (m,12H, CH_(Ar)), 7.58-7.63 (m, 4H, CH_(Ar)), 8.09 (s, 2H, CH_(Ar)).

¹³C NMR (CD₂Cl₂, 125 MHz):

δ=111.5 (2C, CH_(Ar)), 124.0 (2C, C_(quart)), 128.1 (12C, CH_(Ar)),128.3 (2C, C_(quart)), 129.2 (2C, CH_(Ar)), 129.8 (6C, CH_(Ar)), 134.4(6C, C_(quart)), 135.6 (2C, CH_(Ar)), 136.5 (12C, CH_(Ar)), 157.5 (2C,C_(quart)).

Mass (El): m/e=684 (M⁺)

Example 4h Synthesis of 3-bromo-9-phenyl-6-triphenylsilylcarbazole

Reaction Procedure:

A solution of 9-(3-methoxyphenyl)-3,6-dibromo-9H-carbazole (26 g, 1 eq)in dry THF (700 ml) is admixed slowly at −78° C. under argon withn-butyllithium (1.6 M in hexane, 41 ml, 1 eq) and stirred at −78° C. for2 h. After a solution of chlorotriphenylsilane (30 g, 1.5 eq) in dry THF(150 ml) had been added at −78° C., the mixture was warmed to roomtemperature overnight with stirring. Excess butyllithium is hydrolyzedwith saturated ammonium chloride solution. The precipitated reactionproduct is filtered off and washed thoroughly with methylene chloride.The combined methylene chloride filtrates are extracted with water andconcentrated to dryness. The residue is stirred with acetone andfiltered off. Yield 74%.

¹H NMR (CDCl₃, 400 MHz):

δ=8.15 (s, 1H), 8.28 (s, 1H), 7.3-7.7 (m, 24H).

Example 4i Synthesis of 3,6-bis(methyldiphenylsilyl)-9-phenylcarbazole

Reaction Procedure:

A solution of 9-phenyl-3,6-dibromo-9H-carbazole (3.1 g, 1 eq) in dry THF(150 ml) is admixed slowly at −78° C. under argon with n-butyllithium(1.6 M in hexane, 12.2 ml, 2.5 eq) and stirred at −78° C. for 1 h. Aftera solution of diphenylmethylchlorosilane (5.6 g, 3.0 eq) in dry THF (10ml) has been added at −78° C., the mixture is warmed to room temperatureovernight with stirring. Excess butyllithium is hydrolyzed withsaturated ammonium chloride solution. The precipitated product isfiltered off and washed thoroughly with CH₂Cl₂. Column chromatography(SiO₂, 15:1 cyclohexane/CH₂Cl₂) gives the product. Yield 60%.

¹H NMR (CDCl₃, 400 MHz):

δ=0.9 (s, 6H), 7.3-7.4 (m, 14H), 7.4-7.5 (m, 3H), 7.5-7.6 (m, 12H), 8.25(s, 2H).

Example 4j Synthesis of3,6-bis(dimethylpentafluorophenylsilyl)-9-phenylcarbazole

Reaction Procedure:

A solution of 9-phenyl-3,6-dibromo-9H-carbazole (3.1 g, 1 eq) in dry THF(150 ml) is admixed slowly at −78° C. under argon with n-butyllithium(1.6 M in hexane, 12.2 ml, 2.5 eq) and stirred at −78° C. for 1 h. Aftera solution of flophemesyl chloride (6.1 g, 3.0 eq) in dry THF (10 ml)has been added at −78° C., the mixture is warmed to room temperatureovernight with stirring. Excess butyllithium is hydrolyzed withsaturated ammonium chloride solution. The precipitated product isfiltered off and washed thoroughly with CH₂Cl₂. Column chromatography(C18-SiO₂, MeCN) gives the product. Yield 65%.

¹H NMR (CDCl₃, 400 MHz):

δ=0.8 (s, 12H), 7.38 (d, 2H), 7.5 (m, 3H), 7.6 (m, 4H), 8.35 (s, 2H).

Example 4k Synthesis ofbis(9-phenyl-3-triphenylsilylcarbazolyl)dimethylsilane

Reaction Procedure:

Step 1:

A solution of 9-phenyl-3,6-dibromo-9H-carbazole (12 g, 1 eq) in dry THF(230 ml) is admixed slowly at −78° C. under argon with n-butyllithium(1.6 M in hexane, 18.8 ml, 1 eq) and stirred at −78° C. for 1.5 h. Aftera solution of dichlorodimethylsilane (1.9 g, 0.5 eq) in dry THF (20 ml)has been added at −78° C., the mixture is warmed to room temperatureovernight with stirring. Excess butyllithium is hydrolyzed withsaturated ammonium chloride solution. The precipitated product isfiltered off and washed thoroughly with CH₂Cl₂. Column chromatography(SiO₂, 10:1 hexane/EtOAc) gives the product. Yield 74%.

¹H NMR (CDCl₃, 400 MHz): δ=0.7 (s, 6H), 7.25 (dd, 4H), 7.40 (d, 2H),7.42-7.50 (m, 6H), 7.55-7.65 (m, 6H) 8.22 (s, 2H), 8.30 (s, 2H).

Step 2:

A solution of product from step 1 (3.5 g, 1 eq) in dry THF (100 ml) isadmixed slowly at −78° C. under argon with n-butyllithium (1.6 M inhexane, 7.8 ml, 2.5 eq) and stirred at −78° C. for 1.5 h. After asolution of chlorotriphenylsilane (3.6 g, 2.5 eq) in dry THF (20 ml) hasbeen added at −78° C., the mixture is warmed to room temperatureovernight with stirring. Excess butyllithium is hydrolyzed withsaturated ammonium chloride solution. The precipitated product isfiltered off and washed thoroughly with CH₂Cl₂. Boiling with acetone andfiltering off gives the product. Yield: 45%.

¹H NMR (CDCl₃, 400 MHz):

δ=0.65 (s, 6H), 7.28-7.38 (m, 22H), 7.42 (t, 2H), 7.51 (m, 12H), 7.61(d, 12H) 8.20 (s, 2H), 8.32 (s, 2H).

Example 5 Coupling of Brominated Carbazole Derivatives (X═N—H) to SilylCompounds Example 5a Synthesis of 3,6-bis(triphenylsilyl)-9H-carbazolewithout intermediate isolation (method 1)

A solution of 3,6-dibromocarbazole (9.1 g, 1 eq) in dry THF (400 ml) at0° C. under argon is admixed slowly with NaH (60% in mineral oil, 1.3 g,1.2 eq) and stirred at 0° C. for 2 h. After adding a solution ofchlorotriethylsilane (5.1 g, 1.2 eq) in dry THF (80 ml), the solution isstirred at RT (room temperature) for 1 h. The solution is cooled to −78°C. and admixed with n-butyllithium (1.6 M in hexane, 43.8 ml, 2.5 eq)and stirred at −78° C. for 1 h. After adding a solution ofchlorotriphenylsilane (29.8 g, 3.5 eq) in dry THF (100 ml) at −78° C.,the mixture is warmed to room temperature overnight with stirring.Excess butyllithium is hydrolyzed with saturated ammonium chloridesolution. The precipitated product is filtered off and washed thoroughlywith methylene chloride. The combined methylene chloride filtrates areextracted by shaking with water and dried over sodium sulfate. Theorganic phase is admixed with tetra-n-butylammonium fluoride (TBAF, 1 Min THF, 2 ml) and stirred at RT for 4 h. The mixture is concentrateddown to 100 ml. The resulting precipitate is filtered and washed withn-hexane. Yield 66%.

¹H NMR (CDCl₃, 400 MHz): δ=7.4 (m, 20H), 7.6 (m, 14H), 8.18 (s, 2H),8.20 (s, 1H).

Example 5b Synthesis of 3,6-bis(triphenylsilyl)-9H-carbazole withintermediate isolation

i) 3,6-Dibromo-9-triphenylsilylcarbazole

NaH (60% dispersion in oil, 1.5 g, 37 mmol) is added slowly to a coldsolution (0° C.) of 3,6-dibromocarbazole (10.4 g, 31 mmol) in dry THF(1000 ml). After stirring for two hours, a solution of ClSiPh₃ (18.7 g,62 mmol) in dry THF (200 ml) is added at 0° C. The mixture is stirredovernight, and saturated NH₄Cl solution is added. The resulting salt isfiltered off, and the organic phase is separated from the aqueous phase.The aqueous phase is extracted with CH₂Cl₂. The organic phase is washedtwice with water. The combined organic phases are dried over Na₂SO₄.Filtration through SiO₂ gives the desired product (quantitative).

ii) 3,6,9-Tris(triphenylsilyl)carbazole

tert-BuLi (1.7 M in pentane, 58 ml, 99 mmol) is added slowly to a coldsolution (−78° C.) of 3,6-dibromo-9-triphenylsilylcarbazole (90% purity,see i), 13 g, 22 mmol) in dry THF (1000 ml). After stirring at −78° C.for two hours, ClSiPh₃ (34 g, 115 mmol) in dry THF is added. The mixtureis stirred overnight, and saturated NH₄Cl solution is added. Theresulting salt is filtered off, and the organic phase is separated fromthe aqueous phase. The aqueous phase is extracted with CH₂Cl₂. Theorganic phase is washed twice with water. The combined organic phasesare dried over Na₂SO₄. After column chromatography (SiO₂; 5:1cyclohexane:CH₂Cl₂), the pure product is obtained (R_(f)˜0.3, 11 g,53%).

iii) 3,6-Bis(triphenylsilyl)-9H-carbazole

A TBAF solution (1M in THF, 4.6 ml, 4.6 mmol) is added to a solution of3,6,9-tris-(triphenylsilyl)carbazole (8.7 g, 9.2 mmol) in CH₂Cl₂ (150ml). After stirring for one hour, thin layer chromatography showscomplete deprotection. The solvent is removed under reduced pressure,and the residue is heated under reflux in cyclohexane (150 ml). Aftercooling, the suspension is filtered. The residue is filtered throughSiO₂ (10:1 cyclohexane:EtOAc) to obtain the desired product (7.6 g,97%). ¹H NMR (CDCl₃, 400 MHz): δ=7.4 (m, 20H), 7.6 (m, 14H), 8.18 (s,2H), 8.20 (s, 1H).

Example 6 N-Arylation of 3,6-silylated carbazole derivatives (X═N—H)

General Procedure:

3,6-Bis(triphenylsilyl)-9H-carbazole (1 eq), phenyl halide A, potassiumcarbonate and copper powder are heated to 150-200° C. and stirredovernight at this temperature. After cooling to room temperature, themixture is extracted with methylene chloride. The precipitate isfiltered off and purified by column chromatography (silica gel,methylene chloride/cyclohexane).

The table which follows summarizes the data for different N-arylationsof silylated carbazole derivatives which have been carried out accordingto the general procedure:

Equiv. A Equiv. K₂CO₃ Mol % Cu T (° C.) Yield Analysis

14.5 2.5 21 170 61 ¹H NMR (CDCl₃, 400 MHz): δ = 7.3 (dd, 12H), 7.4 (m,8H), 7.6 (d, 12H), 7.65 (d, 2H), 7.95 (s, 1H), 8.1 (s, 2H), 8.2 (s, 2H).

6 2.5 21 160 71 ¹H NMR (CDCl₃, 400 MHz): δ = 3.9 (s, 3H), 7.1 (d, 2H),7.35 (m, 14H), 7.45 (m, 8H), 7.55 (d, 2H), 7.6 (d, 12H), 8.2 (s, 2H).

4 2.5 21 170 50 ¹H NMR (DMF-d7, 400 MHz): δ = 7.5 (m, 18H), 7.6 (d,12H), 7.7 (m, 4H), 8.0 (t, 1H), 8.1 (d, 1H), 8.2 (d, 1H), 8.3 (s, 2H),8.35 (s, 1H).

4 2.5 21 155 80 ¹H NMR (CDCl₃, 400 MHz): δ = 7.3- 7.5 (m, 20H), 7.6 (d,14H), 7.7 (d, 2H), 7.8 (m, 1H), 7.9 (s, 1H), 8.2 (d, 2H).

1.0 Cs₂CO₃  1.75 10 (CuI) 110 62 In nitro- benz. with 0.2 equiv. ofphenan- throline ¹H NMR (CD₂Cl₂, 400 MHz): δ = 7.38 (dd, 12H), 7.43 (m,6H), 7.58 (d, 12H), 7.65 (m, 6H), 8.2 (s, 2H), 8.8 (br, 2H).

2.0 2.5 20 160 73 ¹H NMR (CD₂Cl₂, 400 MHz): δ = 7.38 (m, 12H), 7.42 (m,8H), 7.58 (d, 12H), 7.61 (d, 2H), 8.2 (s, 2H), 9.05 (s, 2H), 9.15 (s,1H).

2.0 2.5 22 190 56 ¹H NMR (CDCl₃, 400 MHz): δ = 7.3- 7.7 (m, 58H), 8.15(s, 1H), 8.22 (s, 2H), 8.28 (s, 1H).

3.9 2.5 20 180 40 ¹H NMR (CDCl₃, 400 MHz): δ = 7.32 (t, 12H), 7.35-7.50(m, 17H), 7.6 (m, 22H), 7.75 (d, 2H), 8.2 (s, 2H).

3.9 2.5 20 170 45 ¹H NMR (CDCl₃, 400 MHz): δ = 2.5 (s, 6H), 7.20 (d,2H), 7.3-7.5 (m, 20H), 7.50-7.61 (m, 16H), 7.65 (d, 2H), 7.8 (dd, 2H),7.9 (d, 2H), 8.2 (s, 2H).

8.0 2.5 20 130 55 ¹H NMR (CDCl₃, 400 MHz): δ = 4.0 (s, 6H), 7.30-7.45(m, 20H), 7.6 (2 x d, total of 14H), 8.2 (s, 2H), 8.45 (s, 2H), 8.75 (s,1H).

3.1 2.5 20 160 40 ¹H NMR (CDCl₃, 400 MHz): δ = 7.35 (dd, 12H), 7.42, (m,6H), 7.50 (m, 6H), 7.58 (m, 16H), 7.72 (m, 6H), 7.88 (dd, 2H), 8.2 (s,2H).

3.0 2.5 20 180 65 ¹H NMR (CDCl₃, 400 MHz): δ = 2.25 (s, 6H), 7.05 (m,10H), 7.14, (s, 1H), 7.35 (m, 13H), 7.42 (m, 8H), 7.5 (d, 2H), 7.6 (d,12H), 8.18 (s, 2H).

6.0 2.5 20 155 85 ¹H NMR (CD₂Cl₂, 400 MHz): δ = 7.30-7.50 (m, 20H), 7.60(m, 15H), 7.95 (br, 1H), 8.2 (s, 2H), 8.7 (br, 1H), 8.8 (br, 1H).

3.5 2.5 20 140 57 ¹H NMR (CDCl₃, 400 MHz): δ = 1.35 (t, 3H), 4.40 (q,2H), 7.4 (m, 20H), 7.60 (m, 14H), 7.63 (t, 1H), 7.75 (d, 1H), 8.12 (d,1H), 8.19 (s, 2H), 8.22 (s, 1H).

0.5 1.5 20 200 37 ¹H NMR (CDCl₃, 400 MHz): δ = 7.32 (dd, 24H), 7.40 (t,12H), 7.56 (m, 28H), 7.62 (d, 2H), 7.94 (d, 4H), 8.10 (t, 1H), 8.18 (s,4H).

2 5   40 210 54 MALDI-MS (m/z) = 1124

Example 7 Trisubstitution of 2,4,6-trichloro-1,3,5-triazine (cyanuricchloride) to prepare2,4,6-tris-(3,6-bis(triphenylsilanyl)carbazol-9-yl)-1,3,5-triazine

General method: 1.70 g (2.50 mmol) of3,6-bis(triphenylsilanyl)-9H-carbazole are dissolved in 50 ml ofabsolute toluene under a nitrogen atmosphere in a 100 ml 2-neck flaskequipped with nitrogen inlet and septum. Subsequently, the solution isadmixed at room temperature with 1.92 ml (2.50 mmol) of sec-butyllithium(1.3M in cyclohexane) over a period of 10 minutes and stirred for afurther 10 minutes. In a 250 ml 3-neck flask equipped with nitrogeninlet, reflux condenser and septum, 0.14 g (0.75 mmol) of cyanuricchloride is dissolved in a mixture of 10 ml of absolute THF and 20 ml ofabsolute toluene under a nitrogen atmosphere. The carbazole solution isadded dropwise to the cyanuric chloride solution by means of a transfercanula over a period of 20 minutes. The reaction mixture is subsequentlyboiled under reflux for 4 hours.

After cooling to room temperature, the solvent is evaporated and theresidue is stirred in 200 ml of hot hexane for 10 minutes. The solidobtained by filtration is washed with diethyl ether, slurried in hotethanol and hot-filtered. The product is purified by means of columnchromatography with a hexane/toluene eluent mixture (1/4, V/V) to obtain0.84 g (53%) of2,4,6-tris(3,6-bis(triphenylsilanyl)carbazol-9-yl)-1,3,5-triazine as awhite solid.

¹H NMR (250 MHz, CDCl₃)

δ (ppm): 8.97 (d, 6H), 8.08 (s, 6H), 7.63 (d, 6H), 7.60-7.53 (m, 30H),7.42-7.16 (m, 60H).

MALDI-TOF: m/z=2126.53 (M⁺)

Example 8 Synthesis and analysis of DBT-MIC

3.00 g (7.6 mmol) of imidazolium salt and 0.89 g (3.8 mmol) of silveroxide are suspended in 100 ml of acetonitrile and stirred at 40° C.overnight. Subsequently, the suspension is concentrated to dryness,taken up with 100 ml of anhydrous o-xylene and metered into a solutionof 0.51 g (0.76 mmol) of [(μ-Cl)_(η) ⁴-1,5-cod)Ir]₂ and 75 ml o-xylenewithin a half hour. Thereafter, the mixture is stirred at roomtemperature for one hour, at 70° C. for two hours and under reflux for48 hours. After cooling, the reaction mixture is filtered. The filtrateis freed of the solvent under reduced pressure. The residue is extractedwith dichloromethane. The extract is freed of the solvent under reducedpressure and then subjected to column chromatography purification(eluent: toluene). Approx. 150 mg (10%) of mer isomer and 70 mg (5%) offac isomer are obtained, in each case as pale yellow powder.

The imidazolium salt is prepared by deprotonating dibenzothiophene withnBuLi in THF and then brominating with 1,2-dibromoethane. The brominateddibenzothiophene is coupled with imidazole with addition of CuI, K₂CO₃in NMP. The imidazolium salt is formed by methylation with MeI in THF.

Meridional Isomer:

Mass (MALDI): m/e=980 (M⁺)

Optical spectroscopy: λ=453 nm, 481 nm (5% in 4b, applied by vapordeposition)

-   -   CIE: X=0.15, Y=0.21 (5% in 4b, applied by vapor deposition)

Facial Isomer:

Mass (MALDI): m/e=980 (M⁺)

Optical spectroscopy: λ=476 nm, 504 nm (2% in PMMA, low temperature)

CIE: X=0.21, Y=0.41 (2% in PMMA, low temperature)

B Use Examples Example 1 Preparation of an OLED comprising9-phenyl-3,6-bis(triphenylsilyl)carbazole (Example 4b) as a matrixmaterial (65% by weight) and as a hole/exciton blocker

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS and neutralizing agent25ORGAN-ACID®) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO.

Thereafter, the organic materials specified below are applied to thecleaned substrate by vapor deposition at a rate of approx. 0.5-5 nm/minat about 10⁻⁸ mbar. The hole conductor and exciton blocker applied tothe substrate is Ir(dpbic)₃ (V1) with a thickness of 30 nm.

(for preparation, see Ir complex (7) in application WO 2005/019373.)

Subsequently, a mixture of 35% by weight of the compound Ir(CN-PMBIC)₃(V2)

and 65% by weight of the compound9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) is applied byvapor deposition in a thickness of 40 nm, the former compound serving asan emitter, the latter as a matrix material.

Subsequently, the example 4b material is applied by vapor depositionwith a thickness of 5 nm as an exciton and hole blocker.

The synthesis of V2 is described in WO 2006/056418.

Next, an electron transporter TPBI(1,3,5-tris(N-phenylbenzylimidazol-2-yl)benzene) is applied by vapordeposition in a thickness of 50 nm, as are a 0.75 nm-thick lithiumfluoride layer and finally a 110 nm-thick Al electrode.

To characterize the OLED, the electroluminescence spectra are recordedat various currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the emitted light output.The light output can be converted to photometric parameters bycalibration with a photometer. To determine the lifetime, the OLED isoperated at a constant current density and the decrease in the lightoutput is recorded. The lifetime is defined as the time taken for theluminance to decrease to half of the initial luminance.

For the OLED described, the following electrooptical data are obtained:

Emission maximum 456 nm CIE(x, y) 0.16; 0.21 Photometric efficiency at 6V 6.5 cd/A Power efficiency at 6 V 3.4 lm/W External quantum yield at 6V 6.8% Luminance at 9 V 1000 cd/m²

Example 2 Production of an OLED comprising9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) as an exciton andhole blocker material

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS and neutralizing agent25ORGAN-ACID®) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO.

Thereafter, the organic materials specified below are applied to thecleaned substrate by vapor deposition at a rate of approx. 0.5-5 nm/minat about 10⁻⁸ mbar. The hole conductor and exciton blocker applied tothe substrate is Ir(dpbic)₃ (V1) with a thickness of 45 nm.

(for preparation, see Ir complex (7) in application WO 2005/019373).

Subsequently, a mixture of 10% by weight of compound V5

and 90% by weight of the compound Ir(dpbic)₃ is applied by vapordeposition in a thickness of 40 nm, the former compound functioning asan emitter, the latter as a matrix material.

The synthesis of V5 is described in the prior application EP0710755.1.

Subsequently, the material 9-phenyl-3,6-bis(triphenylsilyl)carbazole(example 4b) is applied by vapor deposition with a thickness of 10 nm asan exciton and hole blocker.

Next, an electron transporter BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline is applied by vapordeposition in a thickness of 50 nm, as are a 0.75 nm-thick lithiumfluoride layer and finally a 110 nm-thick Al electrode.

To characterize the OLED, the electroluminescence spectra are recordedat various currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the emitted light output.The light output can be converted to photometric parameters bycalibration with a photometer. To determine the lifetime, the OLED isoperated at a constant current density and the decrease in the lightoutput is recorded. The lifetime is defined as the time taken for theluminance to decrease to half of the initial luminance.

For the OLED described, the following electrooptical data are obtained:

Emission maximum 456 nm CIE(x, y) 0.16; 0.21 Photometric efficiency at 4V 15.5 cd/A Power efficiency at 4 V 12.2 lm/W External quantum yield at4 V 10.0% Luminance at 10 V 2000 cd/m²

Example 3 Production of an OLED comprising9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) as a matrixmaterial (93% by weight) and as a hole/exciton blocker

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS and neutralizing agent25ORGAN-ACID®) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO.

Thereafter, the organic materials specified below are applied to thecleaned substrate by vapor deposition at a rate of approx. 0.5-5 nm/minat about 10⁻⁸ mbar. The hole conductor and exciton blocker applied tothe substrate is Ir(dpbic)₃ with a thickness of 45 nm.

(for preparation, see Ir complex (7) in application WO 2005/019373.)

Subsequently a mixture of 7% by weight of compound V5

and 93% by weight of the compound9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) is applied byvapor deposition in a thickness of 40 nm, the former compoundfunctioning as an emitter, the latter as a matrix material.

Subsequently, the material 9-phenyl-3,6-bis(triphenylsilyl)carbazole(example 4b) is applied by vapor deposition with a thickness of 10 nm asan exciton and hole blocker.

Next, an electron transporter TPBI is applied by vapor deposition in athickness of 40 nm, as are a 0.75 nm-thick lithium fluoride layer andfinally a 110 nm-thick Al electrode.

To characterize the OLED, the electroluminescence spectra are recordedat various currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the emitted light output.The light output can be converted to photometric parameters bycalibration with a photometer. To determine the lifetime, the OLED isoperated at a constant current density and the decrease in the lightoutput is recorded. The lifetime is defined as the time taken for theluminance to decrease to half of the initial luminance.

For the OLED described, the following electrooptical data are obtained:

Emission maximum 451 nm CIE(x, y) 0.15; 0.13 Photometric efficiency at aluminance of 7.4 cd/A 1000 cd/m² Power efficiency at a luminance of 10002.0 lm/W cd/m² External quantum yield at a luminance of 6.0% 1000 cd/m²Luminance at 10 V 361 cd/m²

Example 4 Production of an OLED comprising UGH 3 as a matrix materialand as a hole/exciton blocker and9-phenyl-3,6-bis(triphenylsilyl)carbazole as an intermediate layer

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS and neutralizing agent25ORGAN-ACID®) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO.

Thereafter, the organic materials specified below are applied to thecleaned substrate by vapor deposition at a rate of approx. 0.5-5 nm/minat about 10⁻⁸ mbar. The hole conductor and exciton blocker applied tothe substrate is Ir(dpbic)₃ with a thickness of 45 nm.

(for preparation, see Ir complex (7) in application WO 2005/019373.)

Subsequently, a mixture of 7% by weight of compound V5

and 93% by weight of compound UGH3 are applied by vapor deposition in athickness of 40 nm, the former compound functioning as an emitter, thelatter as a matrix material.

Subsequently, the material UGH3 is applied with a thickness of 10 nm asan exciton and hole blocker.

Next, a material combination composed of 4 nm of9-phenyl-3,6-bis(triphenylsilyl)-carbazole (example 4b) and 36 nm ofTPBI as an electron transporter is applied by vapor deposition, as are a0.75 nm-thick lithium fluoride layer and finally a 110 nm-thick Alelectrode.

To characterize the OLED, the electroluminescence spectra are recordedat various currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the emitted light output.The light output can be converted to photometric parameters bycalibration with a photometer. To determine the lifetime, the OLED isoperated at a constant current density and the decrease in the lightoutput is recorded. The lifetime is defined as the time taken for theluminance to decrease to half of the initial luminance.

For the OLED described, the following electrooptical data are obtained:

Emission maximum 451 nm CIE(x, y) 0.15; 0.13 Photometric efficiency at aluminance of 5.1 cd/A 1000 cd/m² Power efficiency at a luminance of 10000.9 lm/W cd/m² External quantum yield at a luminance of 4.4% 1000 cd/m²Luminance at 10 V 40 cd/m²

The ratio of the lifetimes of the OLED according to example 3 and of theOLED according to example 4 is 4:1.

Example 5 Typical working method 1 for the production of an OLED

The ITO substrate used as the anode is first cleaned with commercialdetergents for LCD production (Deconex® 20NS and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in aultrasound bath. To remove possible organic residues, the substrate isexposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO.

Thereafter, the organic materials specified below are applied by vapordeposition to the cleaned substrate at a rate of approx. 0.5-5 nm/min atapprox 10⁻⁸ mbar. The hole conductor and exciton blocker applied to thesubstrate is Ir(dpbic)₃ with a thickness of 45 nm.

(for preparation see Ir complex (7) in the application WO 2005/019373).

Subsequently, a mixture of 7.5% by weight of compound V5

and 92.5% by weight of the compound9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) is applied byvapor deposition in a thickness of 40 nm, the former compoundfunctioning as the emitter, the latter as the matrix material.

Subsequently, the material 9-phenyl-3,6-bis(triphenylsilyl)carbazole(example 4b) is applied by vapor deposition with a thickness of 10 nm asan exciton and hole blocker.

Next, an electron transporter BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) is applied by vapordeposition in a thickness of 50 nm, as are a 0.75 nm-thick lithiumfluoride layer and finally a 110 nm-thick Al electrode.

To characterize the OLED, electroluminescence spectra are recorded atdifferent currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the light output emitted.The light output can be converted to photometric parameters bycalibration with a photometer.

The construction of the particular OLED is specified in the right-handcolumn of table 1 (device structure). The particular OLED is producedaccording to the typical working method specified above. The values forpower efficiency, quantum efficiency (QE) and voltage reported in table1 are relative values, based in each case on a reference OLED which isidentical in terms of structure to the particular OLED and differs fromthe particular inventive OLED in that9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) is used both as amatrix and as an exciton and hole blocker. The values for the powerefficiency, quantum efficiency (QE) and voltage reported in table 1 aredefined as 100% for the particular reference OLED. A comparison of adiode in which 9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) isused both as the matrix and as an exciton and hole blocker with a diodehaving an identical structure in which, instead of9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b), (thesynthetically significantly more difficult to obtain)9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)carbazole is used showsthat the electroluminescence data of the two OLEDs differ from oneanother only insignificantly. The OLED used in each case as thereference OLED, which comprises9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) both as thematrix and as an exciton and hole blocker thus also serves as thereference for an OLED which comprises9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)carbazole both as thematrix and as an exciton and hole blocker.

Voltage (Power at 300 efficiency nits/ (max)/ voltage power QE (max)/ at300 Device structure (ITO 125 +/− efficiency QE nits 20 nm) (max, (max,(stan- (analogous to typical working standard)) standard)) dard) method,exchange of 4b for novel Material Structure Function 100% 100% 100%material) 4b (standard)

matrix + blocker 100 100 100 see working method specified above 6a

blocker 121 123 99 V1 (45 nm)//8.5% V5:4b (40 nm)//6a (10 nm)//BCP (50nm)//LiF//Alu matrix 106 100 103 V1 (45 nm)//8.5% V5:6a (40 nm)//4b (10nm)//BCP (50 nm)//LiF//Alu matrix + 111 100 93 V1 (45 nm)//8.5% V5:6a(40 nm)//6a blocker (10 nm)//BCP (50 nm)//LiF//Alu 6b

blocker  99  98 100 V1 (45 nm)//8.5% V5:4b (40 nm)//6b (10 nm)//BCP (50nm)//LiF//Alu matrix 109 108 95 V1 (45 nm)//8.5% V5:6b (40 nm)//4b (10nm)//BCP (50 nm)//LiF//Alu matrix + 106 106 98 V1 (45 nm)//8.5% V5:6b(40 nm)//6b blocker (10 nm)//BCP (50 nm)//LiF//Alu 6c

matrix + blocker no comp- arable reference values available no comp-arable reference values available 75 V1 (40 nm)//7.5% V5:6c (40 nm)//6c(5 nm)//BCP (50 nm)//LiF//Alu 6d

matrix + blocker no comp- arable reference values available no comp-arable reference values available 87 V1 (40 nm)//7.5% V5:6d (40 nm)//6d(5 nm)//BCP (50 nm)//LiF//Alu 6e

blocker 124 130 94 10% MoO₃:V1 (35 nm)//V1 (10 nm)//7.5% V5:4b (40nm)//6e (10 nm)//BCP (50 nm)//LiF//Alu matrix 118 109 84 10% MoO₃:V1 (35nm)//V1 (10 nm)//7.5% V5:6e (40 nm)//4b (10 nm)//BCP (50 nm)//LiF//Alumatrix + 144 139 78 10% MoO₃:V1 (35 nm)//V1 blocker (10 nm)//7.5% V5:6e(40 nm)//6e (10 nm)//BCP (50 nm)//LiF//Alu 6f

blocker 158 177 92 V1 (45 nm)//7.5% V5:V1 (10 nm)//7.5% V5:4b (40nm)//6f (10 nm)//BCP (40 nm)//LiF//Alu matrix 125 117 74 V1 (45nm)//8.5% V5:V1 (10 nm)//8.5% V5:6f (40 nm)//4b (10 nm)//BCP (40nm)//LiF//Alu matrix + 138 137 65 V1 (45 nm)//8.5% V5:V1 blocker (10nm)//8.5% V5:6f (40 nm)//6f (10 nm)//BCP (40 nm)//LiF//Alu 6m

blocker 113 113 86 NPD (45 nm)//8.5% V5:4b (40 nm)//6m (10 nm)//BCP (40nm)//LiF//Alu matrix 126 124 87 NPD (45 nm)//8.5% V5:6m (40 nm)//4b (10nm)//BCP (40 nm)//LiF//Alu matrix + 151 149 94 NPD (45 nm)//8.5% V5:6mblocker (40 nm)//6m (10 nm)//BCP (40 nm)//LiF//Alu matrix + 130 135 78V1 (45 nm)//8.5% V5:V1 blocker (10 nm)//8.5% V5:6m (40 nm)//6m (10nm)//BCP (40 nm)//LiF//Alu

Example 6

The OLEDs specified below in table 2 are produced according to thetypical working method 1 specified in example 5. The table which followsreports the electroluminescence data (power efficiency, quantumefficiency (QE) and voltage) for various inventive OLEDs. In the OLEDsspecified below, instead of the material9-phenyl-3,6-bis(triphenylsilyl)carbazole (example 4b) according to thetypical working method of example 5, another compound of the formula IIwas used in each case as the matrix material and/or blocker material.Otherwise, the OLEDs specified below do not differ from the OLEDdescribed above.

TABLE 2 Power efficiency QE Device structure (ITO 125 +/− 20 nm) (max)(max) V at 300 nits (analogous to typical working method, MaterialFunction (cd/A) (%) (V) exchange of 4b for novel material) 4a

matrix + blocker 10.8 7.2 8.7 V1 (45 nm)//8.5% V5:4a (40 nm)//4a (10nm)//TPBI (50 nm)//LiF//Alu 4g

blocker 7.9 7.0 9.7 10% MoO₃:V1 (35 nm)//V1 (10 nm)//7.5% V5:4b (40nm)//4g (10 nm)//BCP (40 nm)//LiF//Alu matrix 8.4 7.1 8.9 10% MoO₃:V1(35 nm)//V1 (10 nm)//7.5% V5:4g (40 nm)//4b (10 nm)//BCP (40nm)//LiF//Alu matrix + 9.7 8.2 8.1 10% MoO₃:V1 (35 nm)//V1 (10 blockernm)//7.5% V5:4g (40 nm)//4g (10 nm)//BCP (40 nm)//LiF//Alu

Example 7 Typical working method 2 for production of an OLED

The ITO substrate used as the anode is first cleaned with commercialdetergents for LCD production (Deconex® 20NS and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in anultrasound bath. To remove possible organic residues, the substrate isexposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO.

Thereafter, the organic materials specified below are applied by vapordeposition to the cleaned substrate at a rate of approx. 0.5-5 nm/min atapprox 10⁻⁸ mbar. The hole conductor and exciton blocker applied to thesubstrate is Ir(dpbic)₃ with a thickness of 45 nm.

(for preparation see Ir complex (7) in the application WO 2005/019373).

Subsequently, a mixture of 7% by weight of the compound V6-R

and 93% by weight of the compound Ir(dpbic)₃ (V1) is applied by vapordeposition in a thickness of 40 nm, the former compound functioning asthe emitter, the latter as the matrix material.

Subsequently, the material9-(4-phenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (4b) is applied byvapor deposition with a thickness of 10 nm as an exciton and holeblocker

Next, an electron transporter BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) is applied by vapordeposition in a thickness of 45 nm, as are a 0.75 nm-thick lithiumfluoride layer and finally a 110 nm-thick Al electrode.

To characterize the OLED, electroluminescence spectra are recorded atdifferent currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the light output emitted.The light output can be converted to photometric parameters bycalibration with a photometer.

For the OLEDs described, the following electrooptical data specified intable 3 are obtained:

TABLE 3 Emission Photometric maximum efficiency at 4 V Power efficiencyExternal quantum Luminance at R = Material (nm) CIE(x, y) (cd/A) at 4 V(Im/W) yield at 4 V (%) 10 V (cd/m²) methyl

451/478 0.16; 0.21 13.2 10.4 7.1 490 o-tolyl

455/478 0.17; 0.2  7.7 6.0 5.1 810 o-Tolyl

448/476 0.16; 0.16 9.1 7.2 6.7 740 i-Propyl

449/476 0.16; 0.19 14.6 11.4 9.9 575 Phenyl

449/476 nm 0.16; 0.17 15 11.8 11.2 890

Example 8

The ITO substrate used as the anode is first cleaned with commercialdetergents for LCD production (Deconex® 20NS and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in aultrasound bath. To remove possible organic residues, the substrate isexposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO.

Thereafter, the organic and inorganic materials specified below areapplied by vapor deposition to the cleaned substrate at a rate ofapprox. 0.1-5 nm/min at about 10⁻⁸ mbar. As the doped hole conductor,Ir(dpbic)₃ is doped to an extent of 10% with MoO₃ and applied to thesubstrate with a thickness of 35 nm. A further 10 nm of undopedIr(dpbic)₃ follow as the hole conductor and exciton blocker.

(for preparation see Ir complex (7) in the application WO 2005/019373).

Subsequently, a mixture of 7.5% by weight of the compound V7

and 92.5% by weight of the compound SiCz is applied by vapor depositionin a thickness of 50 nm, the former compound functioning as the emitter,the latter as the matrix material.

Subsequently, the material9-(4-phenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (4b) is applied byvapor deposition with a thickness of 10 nm as an exciton and holeblocker.

Next, an electron transporter BCP2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline is applied by vapordeposition in a thickness of 40 nm, as are a 0.75 nm-thick lithiumfluoride layer and finally a 110 nm-thick Al electrode.

To characterize the OLED, electroluminescence spectra are recorded atdifferent currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the light output emitted.The light output can be converted to photometric parameters bycalibration with a photometer.

For the OLED described, the following electrooptical data are obtained:

Emission maximum 453 nm CIE(x, y) 0.16; 0.17 Photometric efficiency at 8V 10.5 cd/A Power efficiency at 8 V 4.1 lm/W External quantum yield at 8V 7.9% Luminance at 13 V 1100 cd/m²

1-16. (canceled)
 17. An organic light-emitting diode comprising an anodeAn and a cathode Ka and a light-emitting layer E which is arrangedbetween the anode An and the cathode Ka and comprises at least onecarbene complex represented by formula I

in which the symbols are each defined as follows: M¹ is a metal atomselected from the group consisting of metals of group IB, IIB, IIIB,IVB, VB, VIIB, VIIB, the lanthanides and IIIA of the Periodic Table ofthe Elements (CAS version) in any oxidation state possible for theparticular metal atom; carbene is a carbene ligand which may beuncharged or monoanionic and mono-, bi- or tridentate; the carbeneligand may also be a bis- or triscarbene ligand; L is a mono- ordianionic ligand which may be mono- or bidentate; K is an unchargedmono- or bidentate ligand; n is the number of carbene ligands, where nis at least 1 and the carbene ligands in the complex represented byformula I, when n>1, may be the same or different; m is the number ofligands L, where m may be 0 or 1, and the ligands L, when m>1, may bethe same or different; o is the number of ligands K, where o may be 0 or≧1, and the ligands K, when o>1, may be the same or different; p is thecharge of the complex: 0, 1, 2, 3 or 4; W is a monoanionic counterion;where the sum of n+m+o and the charge p depend on the oxidation stateand coordination number of the metal atom, on the charge of the complexand on the denticity of the carbene, L and K ligands, and on the chargeof the carbene and L ligands, with the condition that n is at least 1;and if appropriate at least one further layer, wherein the organiclight-emitting diode comprises at least one compound represented byformula II which is present in the light-emitting layer E or in the atleast one further layer, or both,

in which: X is NR¹, S, O, PR¹, SO₂ or SO; R¹ is substituted orunsubstituted C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, orsubstituted or unsubstituted heteroaryl having from 5 to 30 ring atoms;R², R³, R⁴, R⁵, R⁶, R⁷ are each independently substituted orunsubstituted C₁-C₂₀-alkyl, or substituted or unsubstituted C₆-C₃₀-aryl,or a structure represented by formula (c)

R^(a), R^(b) are each independently substituted or unsubstitutedC₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, or substitutedor unsubstituted heteroaryl having from 5 to 30 ring atoms or asubstituent with donor or acceptor action selected from the groupconsisting of: C₁-C₂₀-alkoxy, C₆-C₃₀-aryloxy, C₁-C₂₀-alkylthio,C₆-C₃₀-arylthio, SiR¹⁴R¹⁵R¹⁶, halogen radicals, halogenated C₁-C₂₀-alkylradicals, carbonyl (—CO(R¹⁴)), carbonylthio (—C═O (SR¹⁴)), carbonyloxy(—C═O(OR¹⁴)), oxycarbonyl (—OC═O(R¹⁴)), thiocarbonyl (—SC═O(R¹⁴)), amino(—NR¹⁴R¹⁵), OH, pseudohalogen radicals, amido (—C═O (NR¹⁴)),—NR¹⁴C═O(R¹⁵), phosphonate (—P(O) (OR¹⁴)₂, phosphate (—OP(O) (OR¹⁴)₂),phosphine (—PR¹⁴R¹⁵), phosphine oxide (—P(O)R¹⁴ ₂), sulfate(—OS(O)₂OR¹⁴), sulfoxide (—S(O)R¹⁴), sulfonate (—S(O)₂OR¹⁴), sulfonyl(—S(O)₂R¹⁴), sulfonamide (—S(O)₂NR¹⁴R¹⁵), NO₂, boronic esters(—OB(OR¹⁴)₂), imino (—C═NR¹⁴R¹⁵)), borane radicals, stannane radicals,hydrazine radicals, hydrazone radicals, oxime radicals, nitroso groups,diazo groups, vinyl groups, sulfoximines, alanes, germanes, boroximesand borazines; R¹⁴, R¹⁵, R¹⁶ are each independently substituted orunsubstituted C₁-C₂₀-alkyl, or substituted or unsubstituted C₆-C₃₀-aryl;q, r are each independently 0, 1, 2 or 3; where, in the case when q or ris 0, all substitutable positions of the aryl radical are substituted byhydrogen, where the radicals and indices in the group represented byformula (c) X′″, R^(5′″), R^(6′″), R^(7′″), R^(a′″), R^(b′″), q′″ andr′″ are each independently as defined for the radicals and indices ofthe compounds represented by formula (II) X, R⁵, R⁶, R⁷, R^(a), R^(b), qand r, wherein, if X is NR¹, at least one of the R¹ to R⁷, R^(a) orR^(b) radicals in compounds represented by formula (II) comprises atleast one heteroatom.
 18. The organic light-emitting diode according toclaim 17, which comprises at least one further layer selected from thegroup consisting of: at least one blocking layer for electrons/excitons,at least one blocking layer for holes/excitons, at least one holeinjection layer, at least one hole conductor layer, at least oneelectron injection layer and at least one electron conductor layer. 19.The organic light-emitting diode according to claim 17, wherein at leastone of the R², R³ and R⁴ radicals or at least one of the R⁵, R⁶ and R⁷radicals, or mixtures thereof, is substituted or unsubstitutedC₆-C₃₀-aryl.
 20. The organic light-emitting diode according to claim 17,wherein the compound represented by formula (II) is a3,6-disilyl-substituted compound represented by formula (IIa):

in which: X is NR¹, S, O, PR¹, SO₂ or SO; R¹ is substituted orunsubstituted C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, orsubstituted or unsubstituted heteroaryl having from 5 to 30 ring atoms;R², R³, R⁴, R⁵, R⁶, R⁷ are each independently substituted orunsubstituted C₁-C₂₀-alkyl or substituted or unsubstituted C₆-C₃₀-arylor a structure represented by formula (c); R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³are each independently hydrogen or are as defined for R^(a) and R^(b),i.e. are each independently substituted or unsubstituted C₁-C₂₀-alkyl,substituted or unsubstituted C₆-C₃₀-aryl, substituted or unsubstitutedheteroaryl having from 5 to 30 ring atoms or a substituent with donor oracceptor action, suitable substituents with donor or acceptor actionhaving been specified above.
 21. The organic light-emitting diodeaccording to claim 17, wherein the R¹ to R⁷, R^(a) and R^(b) radicalsand the X group are each defined as follows: X is NR¹; R¹ is substitutedor unsubstituted C₆-C₃₀-aryl or substituted or unsubstituted heteroarylhaving from 5 to 30 ring atoms; R², R³, R⁴, R⁵, R⁶, R⁷ are eachindependently substituted or unsubstituted C₁-C₂₀-alkyl or substitutedor unsubstituted C₆-C₃₀-aryl, or a structure represented by formula (c);where, in one embodiment, at least one of the R², R³ and R⁴ radicals orat least one of the R⁵, R⁶ and R⁷ radicals, or mixtures thereof, issubstituted or unsubstituted C₆-C₃₀-aryl; R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³ areeach independently hydrogen or are each as defined for R^(a) and R^(b),i.e. are each independently substituted or unsubstituted C₁-C₂₀-alkyl,substituted or unsubstituted C₆-C₃₀-aryl, substituted or unsubstitutedheteroaryl having from 5 to 30 ring atoms or a substituent with donor oracceptor action; R¹⁴, R¹⁵, R¹⁶ are each independently substituted orunsubstituted C₁-C₂₀-alkyl or substituted or unsubstituted C₆-C₃₀-aryl.22. The organic light-emitting diode according to claim 17, wherein theR¹ radical or at least one of the radicals from the group of R², R³ andR⁴ or at least one of the radicals from the group of R⁵, R⁶ and R⁷, ormixtures thereof, is independently substituted or unsubstituted C₆-arylrepresented by formula:

in which p is 0, 1, 2, 3, 4 or 5; R¹⁷ is hydrogen, substituted orunsubstituted C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl,substituted or unsubstituted heteroaryl having from 5 to 30 ring atoms,a substituent with donor or acceptor action, or a radical represented byformula a or b

in which X′ is N or P, and the radicals and indices X″, R^(2′), R^(3′),R^(4′), R^(5′), R^(5″), R^(6′), R^(6″), R^(7′), R^(7″), R^(a′), R^(a″),R^(b′), R^(b″), q′, q″, r′ and r″ are each independently as defined forthe radicals and indices X, R², R³, R⁴, R⁵, R⁶, R⁷, R^(a), R^(b), q andr; or one of the R², R³ and R⁴ radicals or one of the R⁵, R⁶ and R⁷radicals, or mixtures thereof, is a radical represented by formula c

in which the radicals and indices X′″, R^(5′″), R^(6′″), R^(7′″),R^(a′″), R^(b′″), q′″ and r′″ are each independently as defined for theradicals and indices X, R⁵, R⁶, R⁷, R^(a), R^(b), q and r.
 23. Theorganic light-emitting diode according to claim 17, wherein the at leastone further layer which may be present is selected from the groupconsisting of a blocking layer for electrons, a hole injection layer anda hole conductor layer, at least one compound represented by formula(II) being present in at least one of the further layers or thelight-emitting layer, or both, where the compound represented by formula(II) has at least one R¹, R², R³, R⁴, R⁵, R⁶ or R⁷ radical which isselected from the group consisting of substituted or unsubstitutedC₁-C₂₀-alkyl, heteroaryl having from 5 to 30 ring atoms, unsubstitutedC₆-C₃₀-aryl, alkyl-substituted C₆-C₃₀-aryl, C₆-C₃₀-aryl substituted byat least one substituent with donor action, C₆-C₃₀-aryl substituted byheteroaryl having from 5 to 30 ring atoms, and a substituent with donoraction.
 24. The organic light-emitting diode according to claim 17,wherein the at least one further layer which may be present is selectedfrom the group consisting of a blocking layer for holes, an electroninjection layer and an electron conductor layer, at least one compoundrepresented by formula (II) being present in at least one of the furtherlayers or the light-emitting layer, or both, where the compoundrepresented by formula (II) has at least one R¹, R², R³, R⁴, R⁵, R⁶ orR⁷ radical which is selected from the group consisting of C₁-C₂₀-alkylsubstituted by at least one substituent with acceptor action,C₆-C₃₀-aryl substituted by at least one substituent with acceptoraction, C₆-C₃₀-aryl substituted by at least one heteroaryl radicalhaving from 5 to 30 ring atoms, and a substituent with acceptor action.25. A light-emitting layer comprising at least one compound representedby formula (II) according to claim 17 and at least one carbene complexrepresented by formula (I) according to claim
 17. 26. The method ofusing compounds represented by formula (II) according to any of claims17 as matrix material, a hole/exciton blocker material, anelectron/exciton blocker material, a hole injection material, anelectron injection material, a hole conductor material, or an electronconductor material in an organic light-emitting diode which comprises atleast one carbene complex represented by formula I according to claim17, or mixtures thereof.
 27. A device selected from the group consistingof stationary visual display units such as visual display units ofcomputers, televisions, visual display units in printers, kitchenappliances and advertising panels, illuminations, information panels andmobile visual display units, such as visual display units in cellphones,laptops, digital cameras, vehicles and destination displays on buses andtrains, and illumination units comprising at least one organiclight-emitting diode according to claim
 17. 28. A compound representedby formula II

in which: X is NR¹, S, O, PR¹, SO₂ or SO; R¹ is substituted orunsubstituted C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, orsubstituted or unsubstituted heteroaryl having from 5 to 30 ring atoms;R², R³, R⁴, R⁵, R⁶, R⁷ are each independently substituted orunsubstituted C₁-C₂₀-alkyl, or substituted or unsubstituted C₆-C₃₀-aryl,or a structure represented by formula (c)

R^(a), R^(b) are each independently substituted or unsubstitutedC₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, or substitutedor unsubstituted heteroaryl having from 5 to 30 ring atoms or asubstituent with donor or acceptor action selected from the groupconsisting of: C₁-C₂₀-alkoxy, C₆-C₃₀-aryloxy, C₆-C₃₀-arylthio,SiR¹⁴R¹⁵R¹⁶, halogen radicals, halogenated C₁-C₂₀-alkyl radicals,carbonyl (—CO(R¹⁴)), carbonylthio (—C═O (SR¹⁴)), carbonyloxy(—C═O(OR¹⁴)), oxycarbonyl (—OC═O(R¹⁴)), thiocarbonyl (—SC═O(R¹⁴)), amino(—NR¹⁴R¹⁵), OH, pseudohalogen radicals, amido (—C═O (NR¹⁴)),—NR¹⁴C═O(R¹⁵), phosphonate (—P(O) (OR¹⁴)₂), phosphate (—OP(O) (OR¹⁴)₂),phosphine (—PR¹⁴R¹⁵), phosphine oxide (—P(O)R¹⁴ ₂), sulfate(—OS(O)₂OR¹⁴), sulfoxide (—S(O)R¹⁴), sulfonate (—S(O)₂OR¹⁴), sulfonyl(—S(O)₂R¹⁴), sulfonamide (—S(O)₂NR¹⁴R¹⁵), NO₂, boronic esters(—OB(OR¹⁴)₂), imino (—C═NR¹⁴R¹⁵)), borane radicals, stannane radicals,hydrazine radicals, hydrazone radicals, oxime radicals, nitroso groups,diazo groups, vinyl groups, sulfoximines, alanes, germanes, boroximesand borazines; R¹⁴, R¹⁵, R¹⁶ are each independently substituted orunsubstituted C₁-C₂₀-alkyl, or substituted or unsubstituted C₆-C₃₀-aryl;q, r are each independently 0, 1, 2 or 3; where, in the case when q or ris 0, all substitutable positions of the aryl radical are substituted byhydrogen, where the radicals and indices in the group represented byformula (c) X′″, R^(5′″), R^(6′″), R^(7′″), R^(a′″), R^(b′″), q′″ andr′″ are each independently as defined for the radicals and indices ofthe compounds represented by formula (II) X, R⁵, R⁶, R⁷, R^(a), R^(b), qand r; where, in the case that X is NR¹, at least one of the R¹ to R⁷,R^(a) or R^(b) radicals in the compounds represented by formula (II)comprises at least one heteroatom.
 29. A compound according to claim 28,wherein at least one of the R², R³ and R⁴ radicals or at least one ofthe R⁵, R⁶ and R⁷ radicals, or mixtures thereof, is substituted orunsubstituted C₆-C₃₀-aryl.
 30. A compound according to claim 28, whereinthe compound represented by formula (II) is a 3,6-disilyl-substitutedcompound represented by formula (IIa):

in which: X is NR¹, S, O, PR¹, SO₂ or SO; R¹ is substituted orunsubstituted C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl, orsubstituted or unsubstituted heteroaryl having from 5 to 30 ring atoms;R², R³, R⁴, R⁵, R⁶, R⁷ are each independently substituted orunsubstituted C₁-C₂₀-alkyl or substituted or unsubstituted C₆-C₃₀-arylor a structure represented by formula (c); R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³are each independently hydrogen or are as defined for R^(a) and R^(b),i.e. are each independently substituted or unsubstituted C₁-C₂₀-alkyl,substituted or unsubstituted C₆-C₂₀-aryl, substituted or unsubstitutedheteroaryl having from 5 to 30 ring atoms or a substituent with donor oracceptor action, suitable substituents with donor or acceptor actionhaving been specified above.
 31. A compound according to claim 28,wherein the R¹ radical or at least one of the radicals from the group ofR², R³ and R⁴ or at least one of the radicals from the group of R⁵, R⁶and R⁷, or mixtures thereof, are each independently substituted orunsubstituted C₆-aryl represented by formula:

in which p is 0, 1, 2, 3, 4 or 5; R¹⁷ is hydrogen, substituted orunsubstituted C₁-C₂₀-alkyl, substituted or unsubstituted C₆-C₃₀-aryl,substituted or unsubstituted heteroaryl having from 5 to 30 ring atoms,a substituent with donor or acceptor action, or a radical represented byformula a or b

in which X′ is N or P, and the radicals and indices X″, R^(2′), R^(3′),R^(4′), R^(5′), R^(5″), R^(6′), R^(6″), R^(7′), R^(7″), R^(a′), R^(a″),R^(b′), R^(b″), q′, q″, r′ and r″ are each independently as defined forthe radicals and indices X, R², R³, R⁴, R⁵, R⁶, R⁷, R^(a), R^(b), q andr; or one of the R², R³ and R⁴ radicals or one of the R⁵, R⁶ and R⁷radicals, or mixtures thereof, is a radical represented by formula c

in which the radicals and indices X′″, R^(5′″), R^(6′″), R^(7′″),R^(a′″), R^(b′″), q′″ and r′″ are each independently as defined for theradicals and indices X, R⁵, R⁶, R⁷, R^(a), R^(b), q and r.
 32. A processfor preparing compounds represented by formula (II) according to anyclaim 28, comprising the steps of proceeding from a base structurerepresented by formula (III):

where X is NR¹, SO, SO₂, S, O or PR¹ or NH or PH or PPh, the R¹, R^(a),R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals, when the R^(a) and R^(b) radicalsare present in the compounds represented by formula (II), are introducedby one of the following variants a), b), c) or d), Variant a) ia)preparing a precursor compound suitable for introducing the R^(a),R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals, iia) introducing the R¹ radical,iiia) introducing the R^(a), R^(b) radicals, where present, and theSiR²R³R⁴ and SiR⁵R⁶R⁷ radicals; or Variant b) ib) introducing the R¹radical, iib) preparing a precursor compound suitable for introducingthe R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals, iiib) introducing theR^(a), R^(b) radicals, where present, and the SiR²R³R⁴ and SiR⁵R⁶R⁷radicals; or Variant c) ic) preparing a precursor compound suitable forintroducing the R^(a), R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals, iic)introducing the R^(a), R^(b) radicals, where present, and the SiR²R³R⁴and SiR⁵R⁶R⁷ radicals, iiic) introducing the R¹ radical; or Variant d)id) preparing a precursor compound suitable for introducing the R^(a),R^(b), SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals, iid) introducing the R^(a), R^(b)radicals, where present, and the SiR²R³R⁴ and SiR⁵R⁶R⁷ radicals.
 33. Theorganic light-emitting diode according to claim 20, wherein R⁸, R⁹, R¹⁰,R¹¹, R¹², R¹³ are each independently hydrogen, methyl, ethyl, phenyl,CF₃ or SiR¹⁴R¹⁵R¹⁶, wherein at least one of the R¹⁴, R¹⁵ and R¹⁶radicals is substituted phenyl, wherein, if X is NR¹, at least one ofthe R¹ to R⁷, or R⁸ to R¹³ radicals in compounds represented by formula(IIa) comprises at least one heteroatom.
 34. The organic light-emittingdiode according to claim 21, wherein, at least one of the R¹⁴, R¹⁵ andR¹⁶ radicals is substituted phenyl, wherein at least one of R¹ to R⁷ orR⁸ to R¹³ radicals in compounds represented by formula (II) comprises atleast one heteroatom.
 35. The compound according to claim 30, wherein atleast one of the R¹⁴, R¹⁵ and R¹⁶ radicals is substituted phenyl. 36.The organic light-emitting diode according to claim 20, wherein R⁸, R⁹,R¹⁰, R¹¹, R¹², R¹³ are each independently hydrogen, substituted orunsubstituted C₁-C₆-alkyl, substituted or unsubstituted C₆-C₁₀-aryl orSiR¹⁴R¹⁵R¹⁶.